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Ordering number: EN3680C
Monolithic Linear IC
LA4485 5 W, Two-channel Power Amplifier with Very Few External Parts
Overview
The LA4485 is a 5 W, two-channel power amplifier IC that requires a minimum of external parts, making it ideal for radio cassette players and car stereo equipment. The LA4485 eliminates the need for bootstrap capacitors, negative feedback capacitors, and oscillation prevention CR parts, all of which were necessities for power ICs previously. All of these functions are now on chip, keeping the number of external parts to an absolute minimum. The LA4485 is part of the Power (Stylish Power) Series, and supports two modes: dual and BTL.
Package Dimensions
unit : mm
3107-SIP13H
[LA4485]
Features
. 5 W × 2 output power in dual mode, and 15 W in BTL mode . Minimum external parts for the Power Series count: in dual . 4 or 5 partscircuits mode; 3 or 4 parts in BTL mode Protection . . . .
Overvoltage protection Thermal protection DC output short-circuit protection (to VCC and to GND) Circuitry designed to handle +VCC applied to the outputs Pop noise reduction Standby switch Muting function
SANYO : SIP13H
Specifications
Maximum Ratings at Ta = 25°C
Parameter Maximum supply voltage Surge supply voltage Peak output current Allowable power dissipation Operating temperature Storage temperature Symbol VCC max VCC surge * IO peak Pd max Topr Tstg No signal Based on the JASO standard Per channel With infinite heat sink Conditions Ratings 24 50 3.3 15 30 to +80 40 to +150 Unit V V A W °C °C
*: By the type B check point method.
Operating Conditions at Ta = 25°C
Parameter Recommended supply voltage Supply voltage range Recommended load resistance range Symbol VCC VCC op RL Must not be over package Pd Dual BTL Conditions Ratings 13.2 7.5 to 18 2 to 8 4 to 8 Unit V V
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73096HA(II)/D2893TS/9041TS No.3680-1/20
LA4485
Operating Characteristics at Ta = 25°C, VCC = 13.2 V, RL = 4 , Rg = 600 , f = 1 kHz, Dual
Parameter Standby current Quiescent supply current Voltage gain Output power Total harmonic distortion Channel separation Output noise voltage Ripple rejection ratio Symbol Ist ICCO VG1 VG2 PO1* P O2 THD CH sep VNO SVRR Conditions Pin 9 to GND, Standby switch OFF Rg = 0 Dual: VO = 0 dBm BTL: VO = 0 dBm Dual: THD = 10% BTL: THD = 10% PO = 1 W VO = 0 dBm, Rg = 0 Rg = 0, 20 Hz to 20 kHz bandpass filter Rg = 0, 20 Hz to 20 kHz bandpass filter, fR = 100 Hz, VR = 0 dBm, decoupling capacitor connected min 40 43 4 11 45 typ 80 45 51 5 15 0.15 55 0.15 50 max 10 160 47 Unit µA mA dB dB W W % dB mV dB
0.8 0.5
40
*: PO1 = 6 W (typ) when VCC = 14.4 V Voff ± 250 mV for BTL-mode Pd max Ta
Infinite heat sink
Al heat sink mounting conditions Mounting torque 39 Nvcm. Flat washer with silicone grease applied
Allowable power dissipation, Pd max W
No heat sink
Ambient temperature, Ta °C
Large signal VCC Small signal VCC
Equivalent Circuit Block Diagram
FILTER
Filter
CH1 IN
Input amp CH1
Pre drive amp
Output-to-ground short-circuit protection
Output amp
Output-to-supply short-circuit protection
CH1 OUT
Thermal shutdown protection
Small signal GND
REF amp
Overvoltage protection
Output-to-supply short-circuit protection
Large signal GND
BTL IN CH2 IN
Input amp CH2
Pre drive amp
Output amp
Output-to-ground short-circuit protection
CH2 OUT
Standby switch
Mute
BTL OUT
STANDBY
MUTE
No.3680-2/20
LA4485
Recommended LA4485 External Parts Arrangement (Dual-mode)
95.0 × 67.0 mm2
IC Usage Notes
Maximum ratings Care must be taken when operating the LA4485 close to the maximum ratings as small changes in the operating conditions can cause the maximum ratings to be exceeded, thereby breakdown will be caused. Printed circuit board connections Care must be taken when designing the circuit of printed board so as not to form feedback loops, particularly with the small-signal and large-signal ground connections. Notes on LA4485 heatsink mounting 1. 2. 3. 4. 5. 6. Mounting torque must be in the range 39 to 59 Nvcm. The spacing of the tapped holes in the heatsink must match the spacing of the holes in the IC tab. Use screws with heads equivalent to truss head machine screws and binding head machine screws stipulated by JIS for the mounting screws. Furthermore, washers must be used to protect the surface of the IC tab. Make sure that there is no foreign matter, such as cutting debris, between the IC tab and the heatsink. If a heat conducting compound is applied between the contact surfaces, make sure that it is spread uniformly over the entire surface. Because the heatsink mounting tab and the heatsink are at the same electric potential as the chip's GND (large signal GND), care must be taken when mounting the heatsink on more than one device. The heatsink must be mounted before soldering the pins to the PCB.
Comparison of External Parts Required
External parts Output coupling capacitors Input coupling capacitors Bootstrap capacitors Feedback capacitors Filter capacitor Phase compensating capacitor Oscillation-quenching mylar capacitors Oscillation-quenching resistors Others Total (for dual-mode) Existing device Yes Yes Yes Yes Yes Yes Yes Yes No 15 to 16 parts LA4485 Yes Yes No No Optional No No No Optional 4 to 6 parts
Note: Supply capacitors, contained within the power IC, are not counted in both existing and new devices. No.3680-3/20
LA4485
Operating Pin Voltages at VCC = 13.2 V
Pin No. 1 2 3 4 5 6 7 8 9 10 11 12 13 Name CH1 IN CH2 IN SS GND BTL IN BTL OUT FILTER LS VCC SS VCC STANDBY MUTE CH2 OUT LS GND CH1 OUT Function Channel 1 input. Channel 2 input. Small-signal ground BTL-mode feedback input. BTL-mode feedback output. Filter capacitor connection. Large-signal supply Small-signal supply Standby control input. Mute control input. Channel 2 output. Large-signal ground Channel 1 output. Pin voltage (Reference value) 1.4 V (2 VBE) 1.4 V (2 VBE) 0V 45 mV 3.1 V (61/4 VCC) 6.6 V (61/2 VCC) 13.2 V (VCC) 13.2 V (VCC) 5V 0V 6.3 V 0V 6.3 V
Note: Each pin is so arranged lest the IC should be broken even if inserted reversely.
LA4485 Sample Application Circuit
No.3680-4/20
LA4485
VN VCC
Rg = 0 standby + 5 V
ICCO VCC Quiescent supply current, ICCO mA
RL = 4 Rg = 0
RL = 4 (dual)
Output pin voltage, VN V
Overvoltage cutoff
ICCO
Muting on
VCC = 7.5 V Cutoff for waveform carrying signal Muting on
Supply voltage, VCC V lst VCC
CVCC = 0.15 µF (mylar) Rg = 0 Standby to GND
Supply voltage, VCC V PO VIN
VCC = 13.2 V RL = 4 f = 1 kHz Rg = 600
Standby current, Ist µA
Supply voltage, VCC V THD PO Total harmonic distortion, THD % Total harmonic distortion, THD %
Output power, PO W
Input voltage, VIN mV THD f
Output power, PO W f Response Total harmonic distortion, THD %
Frequency, f Hz THD VCC
Response dB
Frequency, f Hz
Supply voltage, VCC V No.3680-5/20
LA4485
PO VCC Current drain, ICC (2CH) A ICC PO
Dual Rg = 600 f = 1 kHz
Output power, PO W
Supply voltage, VCC V Pd PO Power dissipation, Pd (2CH) W Power dissipation, Pd (2CH) W
Dual RL = 2
Output power, PO (1CH) W Pd PO
Dual RL = 3
Output power, PO (1CH) W Pd PO Power dissipation, Pd (2CH) W Power dissipation, Pd (2CH) W
Dual RL = 4
Output power, PO (1CH) W Pd PO
Dual RL = 6
Allowable power dissipation, Pd max (2CH) W
Output power, PO (1CH) W Pd PO Power dissipation, Pd (2CH) W
Dual RL = 8
Output power, PO (1CH) W Pd max VCC
Dual Ta = 25°C
Output power, PO (1CH) W
Supply voltage, VCC V No.3680-6/20
LA4485
CH sep f Channel separation, CH sep dB
Leakage from CH2 to CH1
SVRR VR Ripple rejection ratio, SVRR dB
Leakage from CH1 to CH2
Frequency, f Hz SVRR VCC Ripple rejection ratio, SVRR dB Ripple rejection ratio, SVRR dB
Supply ripple voltage, VR mV SVRR fR
Supply voltage, VCC V ICCO Ta Quiescent current, ICCO mA Output pin voltage, VN V
Ripple frequency, fR Hz VN Ta
Ambient temperature, Ta °C PO Ta Output noise voltage, VNO mV
Ambient temperature, Ta °C VNO Rg
VCC = 13.2 V RL = 4 BPF = 20 Hz to 20 kHz Rg = 0 0.12 mV
Output power, PO W
Temperature characteristic due to output capacitor CO = 1000 µF
Ambient temperature, Ta °C
Source resistance, Rg No.3680-7/20
LA4485
Output DC trace
Speaker terminal VCC = 13.2 V, standby supply +5 V, RL = 4 , Rg = 0 Main switch ON/OFF test
Output DC trace
Speaker terminal VCC = 13.2 V, standby supply +5 V, RL = 4 , Rg = 0 Standby switch ON/OFF text VCC = 13.2 V, RL = 4 , Rg = 0, Mute ON/OFF
Switching noise decreases as CIN = 0.22 µF (Input) is increased. (ex. 2.2 µF)
VCC = 13.2 V, RL = 4 , Rg = 600 , THD = 10%, f = 1 kHz, Output DC waveform
No.3680-8/20
LA4485
Dual-mode Operation Notes
. Use the input capacitor C
Start-up time (ts)
IN
in the range of 0.22 µF to 1.0 µF.
CIN = 0.22 µF 0.15 s Somewhat noticeable CIN = 1.0 µF 0.25 s Good
Parameter
Attack noise when using the muting function
. The DC (filter) capacitor should be 100 µF or greater.
Parameter Standby-off output capacitor discharge circuit Ripple rejection ratio (SVRR) VN rise rate when main or standby is turned ``on''
Speaker turn-ON transient noise increased significantly when CIN is 2.2 µF or greater.
100 µF or less *1. Does not operate. Repeated on/off: poor Somewhat worse 40 dB Fast
100 µF or more *2. Operates normally. On/off: good Good 50 dB Slow
Note: *1. Slow as a result of natural discharge. *2. Approximately 0.3 seconds as a result of forced discharge.
. Use the standby supply capacitor in the range of 0.22 µF to 0.47 µF.
The VN trace for standby OFF changes and speaker turn-ON transient noise is increased significantly when the capacitor is 1 µF or greater. If the standby function is not used, this capacitor must be removed and pin 9 must be pulled up to the power supply.
. The output capacitor's recommended value for C
. The recommended power supply capacitor is approximately 2,200 µF, but other capacitors than 2,200 µF can be used according
to the application's design. Using a capacitor with this value, the load on the supply can be as high as 56 while still providing good supply stability during momentary supply glitches. Note that using a 0.15 µF capacitor can cause oscillations if the supply impedance increases. (Example: Mild oscillation results if the power supply capacitor is open.)
O is 1,000 µF. Smaller capacitance will worsen the roll-off frequency fL and PO in a low range.
. STANDBY pin 9 IC internal circuit
. MUTE pin 10 IC internal circuit
No.3680-9/20
LA4485
. Input pin 1/2 IC internal circuit
. Output pin 11/13 IC internal circuit
SS VCC Bias LS VCC Driver Power transistor
Standby line
Driver Power transistor
Upward/Downward PNP Driver Format LS GND
. The minimum configuration for dual-mode operation
No standby function SVRR 6 40 dB CO = 1000 µF CIN = 2.2 µF
(Four-point method)
No.3680-10/20
LA4485
. Insert capacitors of 1000 pF between each input and ground to prevent external noise. . When the load (R ) or the supply voltage (V ) is increased, turning the standby switch or the main switch on under strong
L CC
input conditions will activate the IC's internal pseudo ASO protection circuit for the upper power transistor (VCE × ICP). This causes output oscillations or intermittent operation (The reference area is shown in Figure 1 below). However, strong input tests after the bias has stabilized have no problems. They also protect the upper power transistors close to the limits of ASO when all signal switches are on. Therefore, when using this IC under these conditions, the circuit design should obey the following condition: Signal generation time > Start-up time of the power amplifier IC or some other method of attaining the zero-volume condition should be adopted.
. An undervoltage protection circuit operates when the voltage is 7.5 V or lower.
This figure shows the pseudo ASO protection area when strong signal is input, and switch is ON: the upper power transistors have an area where VCE × ICP load is caused.
Input voltage, VIN mV rms
PHOTO-2 VCC = 15 V RL = 3 PHOTO-1 VCC = 13.2 V RL = 2 RL = 4 Design center
Dual-mode operation f = 1 kHz Dual channel drive Non-inductive load Ta = 25°C Standby switch ON in a typical application
Supply voltage, VCC V Strong signal input after switch-ON is OK. In BTL-mode operation, the load is RL × 2 Figure 1
No.3680-11/20
LA4485
i) The operating condiations for the PHOTO-1 series in dual mode are VCC = 13.2 V, RL = 2 , f = 1 kHz, VIN = 50 mV and standby switch ON.
``X-Y path observed within the normal area'': checking each channel Output waveforms Transition Stabilization
icp A
Current and voltage waveforms
Power transistor CE voltage V * Plot each point on the power transistor ASO curve. Refer to Figure 2.
icp A
VCE V
Power transistor CE voltage V
VCE V
``VCC VCE'' added, heavy load
ICP (Y)
icp A
VCE (X)
Transition
Stabilization IE VCB
Upper power transistor The load line becomes more closely aligned with the vertical axis because of the load.
Emitter current, IE A
Shifting load line at start-up under large-signal conditions
Collector-base voltage, VCB V Figure 2
No.3680-12/20
LA4485
ii) The operating conditions for the PHOTO-2 in dual mode are VCC = 15 V, RL = 3 , f = 1 kHz, VIN = 100 mV and standby switch ON.
``X-Y path observed within the normal area'' Output waveforms Transition Stabilization
icp A
icp A
Current and voltage waveforms
Power transistor CE voltage V
Power transistor CE voltage V
icp A
VCE V
* Plot each point on the power transistor ASO curve. Refer to Figure 3.
Transition
Emitter current, IE A
Collector-base voltage, VCB V Figure 3
Stabilization IE VCB
Shifting load line at start-up under large-signal conditions
No.3680-13/20
LA4485
LA4485, BTL Sample Application Circuit
Noninverting
Inverting
PO VIN Total harmonic distortion, THD %
THD PO
Output power, PO W
Input voltage, VIN mV
Output power, PO W
No.3680-14/20
LA4485
PO VCC f Response
Output power, PO W
Supply voltage, VCC V THD f Total harmonic distortion, THD %
Response dB
Frequency, f Hz ICC PO
Frequency, f Hz Pd PO
Current drain, ICC A
Output power, PO W Pd PO Power dissipation, Pd W
Power dissipation, Pd W
Allowable power dissipation, Pd max W
Output power, PO W Pd max VCC
Output power, PO W
Supply voltage, VCC V No.3680-15/20
LA4485
BTL
Speaker terminal
VCC = 13.2 V, standby +5 V, RL = 4 , Rg = 0 Main switch ON/OFF test BTL
Speaker terminal
Noninverting
VCC = 13.2 V, standby +5 V, RL = 4 , Rg = 0 Standby switch ON/OFF test BTL VCC = 13.2 V RL = 4 Rg = 0 Mute ON/OFF
Inverting
Measurement
Noninverting
Inverting BTL
Note: Switching noise decreases as CIN = 0.22 µF (input) is increased. (ex. 2.2 µF)
VCC = 13.2 V, RL = 4 , Rg = 600 , THD = 10%, f = 1 kHz Output DC waveform
No.3680-16/20
LA4485
BTL-mode Operation Notes
In BTL mode, channel 1 should be non-inverted and channel 2 should be inverted. Use the input capacitor CIN in the range 0.22 µF to 2.2 µF. Use the standby supply capacitor in the range 0.22 µF to 1.0 µF. When the capacitor is 2.2 µF or more, the VN trace for standby-off changes, and the switching noise increases significantly. The recommended DC (filter) capacitor is 100 µF or greater. The BTL-mode coupling capacitor should be 2.2 µF. When this capacitor is decreased, the output power is decreased. However, when this capacitor is increased, speaker turn-ON transient noise is increased significantly. In BTL mode, the ripple rejection ratio (SVRR) is approximately 40 dB. This is because the output ripple portion of the noninverted side penetrates the BTL coupling end, so that ripple on the inverted side is large. The following method is described as one external measure:
. . . . .
SS VCC
LS VCC
This measure yields an SVRR of approximately 50 dB. Note that the Rx loss voltage is approximately 1 V, and the PO loss is about 1.0 to 1.5 W (to the 15 W level).
. Example of minimum parts for BTL operation
Noninverting
No standby function SVRR 6 40 dB CIN = 2.2 µF CBTL = 2.2 µF (Three point method)
Inverting
Dual-mode short-circuit test circuit
1 Load short-circuit (to ground) 2 Output-to-supply short-circuit 3Output-to-ground short-ciruit
No.3680-17/20
LA4485
. Taking BTL coupling into consideration, the output-to-supply/output-to-ground protector is two-sided in order to protect both the
IC and the speaker. Short-circuit to GND protection
Current × voltage detector
Self-holding positive feedback circuit
Reset circuit
CH1/CH2 Upper/lower power transistor control
When using this method (simultaneously shorting the outputs to supply and to ground) In BTL mode, the IC protection function works even in noninverted output output-to-supply mode, inverted output output-to-ground mode. (The reverse is also OK.) Reference Value (a) Short-circuit test for dual-mode operation after the main and standby switches are turned ON. Conditions: 1 VCC = 10 to 16 V, RL = 4 and PO = 1 to 5 W (variable) for load short-circuit 2 VCC = 10 to 16 V, RL = 4 , Rg = 0 (no signal) for output-to-supply short-circuit 3 VCC = 10 to 16 V, RL = 4 , Rg = 0 (no signal) for output-to-ground short-circuit. Z: impedance
1 Load short-circuit
j: no device breakdown
2 Output-to-supply short-circuit One-time test Z=0 Z = 0.5 j Repeated switching test Z=0 j Z = 0.5 j 3 Output-to-ground short-circuit One-time test Z=0 j Z = 0.5 j Repeated switching test Z=0 j Z = 0.5 j
j
j
(b) Short-circuit test for dual-mode operation (opposite flow of (a)) after the main and standby switches are turned ON. Conditions: same as (a)
1 Load short-circuit
j: No device breakdown
2 Output-to-supply short-circuit One-time test Repeated switching test Z=0 j Z = 0.5 j 3 Output-to-ground short-circuit One-time test Z=0 j Z = 0.5 j Repeated switching test Z=0 j Z = 0.5 j
Z=0 j j
Z = 0.5 j
(Note) Shorting the outputs to ground when muting is active can result in device breakdown.
. BTL-mode short-circuit test circuit
Noninverting
Inverting
1 Load short-circuit 2 Output-to-supply short-circuit 3 Output-to-ground short-circuit
No.3680-18/20
LA4485
Reference Value (a) Short-circuit test for BTL-mode operation after the main and standby switches are turned ON. Conditions: 1 VCC = 10 to 16 V, RL = 4 and PO = 1 to 15 W (variable) for load short-circuit 2 VCC = 10 to 16 V, RL = 4 , Rg = 0 (no signal) for output-to-supply short-circuit 3 VCC = 10 to 16 V, RL = 4 , Rg = 0 (no signal) for output-to-ground short-circuit. Z: impedance
1 Load short-circuit
j: no device breakdown
2 Output-to-supply short-circuit One-time test Z=0 Z = 0.5 j Repeated switching test Z=0 j Z = 0.5 j 3 Output-to-ground short-circuit One-time test Z=0 j Z = 0.5 j Repeated switching test Z=0 j Z = 0.5 j
j
j
(b) Short-circuit test for BTL-mode operation (opposite flow of (a)) after the main and standby switches are turned ON. Conditions: same as (a)
1 Load short-circuit
j: No device breakdown
2 Output-to-supply short-circuit One-time test Repeated switching test Z=0 j Z = 0.5 j 3 Output-to-ground short-circuit One-time test Z=0 j Z = 0.5 j Repeated switching test Z=0 j Z = 0.5 j
Z=0 j j
Z = 0.5 j
(Note) Shorting the outputs to ground when muting is active can result in device breakdown.
. Power supply positive surge
JASO test
The power supply line positive surge breakdown margin has been increased by using the built-in overvoltage protection circuits (VCCX = 28 V) to cut off all bias circuits/change the base-emitter reverse of the output stage. In other words, the breakdown margin is being raised by changing output stage groups that operate as the VCEO (VCER) type to the VCES (VCBO) type.
No.3680-19/20
LA4485
CC to output pins If the power supply pin is floating under the power supply capacitor insertion conditions, and +VCC comes into contact with output lines (a) and (b) as shown in the diagram above, the IC's internal upper power transistor will generally be damaged. The LA4485 has a protective bypass circuit on chip. However, it is dangerous if the power supply capacitor is greater than 2200 µF.
. Test of application of +V
Floating
No products described or contained herein are intended for use in surgical implants, life-support systems, aerospace equipment, nuclear power control systems, vehicles, disaster/crime-prevention equipment and the like, the failure of which may directly or indirectly cause injury, death or property loss. Anyone purchasing any products described or contained herein for an above-mentioned use shall: 1 Accept full responsibility and indemnify and defend SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and distributors and all their officers and employees, jointly and severally, against any and all claims and litigation and all damages, cost and expenses associated with such use: 2 Not impose any responsibility for any fault or negligence which may be cited in any such claim or litigation on SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and distributors or any of their officers and employees jointly or severally. Information (including circuit diagrams and circuit parameters) herein is for example only; it is not guaranteed for volume production. SANYO believes information herein is accurate and reliable, but no guarantees are made or implied regarding its use or any infringements of intellectual property rights or other rights of third parties. This catalog provides information as of July, 1996. Specifications and information herein are subject to change without notice.
No.3680-20/20