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L291
5 BIT - D/A CONVERTER AND POSITION AMPLIFIER
5 BI T D/A CONVERT ER (1/2 LSB MAX LINEARITY ERROR); ERROR AMPLIFIER; POSITION AMPLIFIER. DESCRIPTION The L291, a monolithic LSI circuit in a 16-lead dual in-line plastic package, is intended for use with the L290 and L292 to form a complete 3 chip DC motor positioning system for applications such as carriage/daisy-wheel position control in typewriters. The L290/291/292 system can be directly controlled by a microprocessor.
DIP-16 (Plastic 0.25) ORDER CODE : L291B
ABSOLUTE MAXIMUM RATINGS
Symbol Vs Ptot Tstg, Tj Supply Voltage Total Power Dissipation Tamb = 70 °C Storage and Junction Temperature Parameter Value ± 15 1 - 40 to 150 Unit V W °C
SYSTEM BLOCK DIAGRAM
October 1991
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CONNECTION DIAGRAM (top view)
BLOCK DIAGRAM
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TEST CIRCUIT
THERMAL DATA
Symbol R th-j-amb Parameter Thermal resistance junction-ambient Max Value 80 Unit °C/W
ELECTRICAL CHARACTERISTICS (refer to the circuit, S1 and S2 in (a), Vs = ± 12 V, Tamb = 25 °C, unless otherwise specified)
Symbol Vs Id Parameter Supply Voltage Quiescent Drain Current Test conditions Min. ± 10 6.5 Typ. Max. ± 15 10 Unit V mA
POSITION AMPLIFIER
Vstrobe Enable Voltage Level VL(S in (a)) * VH(S in (b)) * Vos Ib Vo VR Output Offset Voltage (pin 16) Input Bias Current (pin 15) Output Voltage Swing (pin 16) Residual Output Voltage (pin 16) Vstrobe = VL ; GV = 20 dB Vstrobe = VL Vstrobe = VL ; S2 in(b) ; Vs = ± 10.8 V Vstrobe = VH ±9 ± 20 0 2.4 0.8 + Vs ± 50 0.3 V V mV µA V mV
* See block diagram and the note for Position Amplifier.
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ELECTRICAL CHARACTERISTICS (continued)
Symbol Parameter Test conditions Min. Typ. Max. Unit
D/A CONVERTER
I
ref
Current Reference Input Range (pin 9) Current Reference Offset Voltage (pin 9) Outpur Current Range (pin 12) Outpur Current (pin 12) Iref = 0.722 mA SC1 to SC5 = L SIGN = L(IO1) SIGN = H(IO2) Iref = 0.3 to 1.2 mA All Inputs High
0.3
1.2 ± 20 1.4
mA mV mA
Vos Io Io
-1.358 +1.358 -21
-1.4 +1.4
-1.442 mA +1.442 +21 1.61 ± 0.4 µA %FS µA
Io Linearity Error Ios Pin 12 Output Offset Current (including Error Anpifier bias current) Low Voltage Level (digital inputs) High Voltage Level (digital inputs) Digital Input Current (low state) Digital Inputs Current (high state)
Io1+Io2 Iref = 0.722 mA All Inputs High
VL VH IL IH
0 SC1 = LSB SC5 = MSB VL = 0.4 V VH = + VS 2.4
0.8 +VS -50 1
V V µA µA
ERROR AMPLIFIER
Vos Output Offset Voltage (pin 1) Iref = 0.5 mA; All Inputs High Gv = 40 dB Io Vo Output Current (pin 1) Output Voltage Swing (pin 1) All Inputs High S1 in (b); RL = 10 K ± 7.4 ±5 ± 8.4 mA Vp ± 200 mV
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D/A CONVERTER The L291 contains a 5-bit D/A converter accepting a binary code and generating a bipolar output current, the polarity of which depends on the SIGN input. The amplitude of the output current is a multiple of a reference current Iref. The maximum output current is IFS = ± 31 Iref 16
The following table shows the value of Io for different input codes. Note that the input bits are active low.
DIGITAL INPUT WORD SIGN L L X H H X = indifferent L = low H = High SC5 MSB L H H H L SC4 L H H H L SC3 L H H H L SC2 L H H H L SC1 LSB L L H L L
Output Current IO 31 16 1 16 O + + 1 16 31 16 Iref Iref Iref
- -
Iref
This D/A converter has a maximum linearity error or equal to ± 1/2 LSB (or ± 1.61% Full Scale); that guarantees its monotonicity. ERROR AMPLIFIER In order to have a good stability, the Error Amplifier must work with a closed loop gain greater or equal than 20 dB. POSITION AMPLIFIER It is inserted by means of the strobe signal, TTl and microprocessor compatible. Its output is connected to pin 16 when Vstrobe = Low ; pin 16 grounded for Vstrobe = High. SYSTEM DESCRIPTION : refer to the L292 data sheet.
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Figure 1. Complete Application Circuit.
D1 to D4 :
{
VF 1.2V @ I = 2A trr 200 ns
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DIP-16 PACKAGE MECHANICAL DATA
DIM. MIN. a1 B b b1 D E e e3 F I L Z 3.3 1.27 8.5 2.54 17.78 7.1 5.1 0.130 0.050 0.51 0.77 0.5 0.25 20 0.335 0.100 0.700 0.280 0.201 1.65 mm TYP. MAX. MIN. 0.020 0.030 0.020 0.010 0.787 0.065 inch TYP. MAX.
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Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of SGS-THOMSON Microelectronics. © 1994 SGS-THOMSON Microelectronics - All Rights Reserved SGS-THOMSON Microelectronics GROUP OF COMPANIES Australia - Brazil - France - Germany - Hong Kong - Italy - Japan - Korea - Malaysia - Malta - Morocco - The Netherlands - Singapore Spain - Sweden - Switzerland - Taiwan - Thaliand - United Kingdom - U.S.A.
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