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INTEGRATED CIRCUITS
DATA SHEET
For a complete data sheet, please also download:
· The IC04 LOCMOS HE4000B Logic Family Specifications HEF, HEC · The IC04 LOCMOS HE4000B Logic Package Outlines/Information HEF, HEC
HEF4938B Dual precision monostable multivibrator
Preliminary specification File under Integrated Circuits, IC04 January 1995
Philips Semiconductors
Preliminary specification
Dual precision monostable multivibrator
FEATURES · Separate reset inputs · Triggering from leading or trailing edge · ICC category: MSI DESCRIPTION The HEF4938B is a dual retriggerable-resettable monostable multivibrator. Each multivibrator has an active LOW trigger/retrigger input (I0), an active HIGH trigger/retrigger input (I1), an overriding active LOW direct reset input (CD), an output (O) and its complement (O), and two pins (CTC and RCTC) for connecting the external timing components Ct and Rt. Typical pulse width variation over temperature range is ±0.2%. The HEF4938B may be triggered by either the positive or the negative edges of the input pulse and will produce an accurate output pulse with a pulse width range of 10 µs to infinity. The duration and accuracy of the output pulse are determined by the external timing components Ct and Rt. The output pulse width (T) is equal to Rt × Ct. The linear design techniques in LOCMOS guarantee precise control of the output pulse width. A LOW level at CD terminates the output pulse immediately. Schmitt-trigger action in the inputs makes the circuit highly tolerant for slower rise and fall times. FUNCTION TABLE INPUTS I0 H X Notes 1. H = HIGH voltage level 2. L = LOW voltage level January 1995 I1 L X CD H H L L H 3. X = state is immaterial 4. = positive-going transition 5. = negative-going transition 6. 7. = positive output pulse = negative output pulse 2 OUTPUTS O O TYPE NUMBER PINS HEF4938B PIN DESCRIPTION PIN NO. 1, 15 2, 14 3, 13 4, 12 5, 11 6, 10 7, 9 8 16 SYMBOL CTC A, CTC B RCTC A, RCTC B CDA, CDB I1A, I1B I0A, I0B OA, OB OA, OB VSS VDD 16 PIN POSITION DIL ORDERING AND PACKAGE INFORMATION PACKAGES
HEF4938B
MATERIAL plastic
CODE SOT38Z
NAME AND FUNCTION external capacitor connections external capacitor/resistor connections direct reset input (active LOW) input (LOW-to-HIGH triggered) input (HIGH-to-LOW triggered) output complementary output (active LOW) ground (0 V) positive supply voltage
Fig.1 Pin configuration.
Fig.2 Functional diagram.
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Dual precision monostable multivibrator HEF4938B
Preliminary specification
Philips Semiconductors
Preliminary specification
Dual precision monostable multivibrator
FUNCTION TABLE INPUTS I0 H X Notes 1. H = HIGH state (the more positive voltage) 2. L = LOW state (the less positive voltage) 3. X = state is immaterial 4. 5. 6. 7. = positive-going transition = negative-going transition = positive output pulse = negative output pulse Fig.4 X I1 L CD H H L L H OUTPUTS O O
HEF4938B
Connection of the external timing components Rt and Ct.
DC CHARACTERISTICS VSS = 0 V Tamb (°C) VDD V Supply current active state (see note) Input leakage current (pins 2 and 14) Note 1. Only one monostable is switching: current present during output pulse (output O is HIGH). 15 ±IIN 300 1000 nA 5 10 15 ID SYMBOL -40 TYP. MAX. + 25 TYP. 55 150 220 MAX. + 85 TYP. MAX. µA µA µA
January 1995
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Philips Semiconductors
Preliminary specification
Dual precision monostable multivibrator
AC CHARACTERISTICS VSS = 0 V; Tamb = 25 °C; CL = 50 pF; input transition times 20 ns. PARAMETER Propagation delay I0, I1 to O HIGH to LOW Propagation delay I0, I1 to O LOW to HIGH Propagation delay CD to O HIGH to LOW Propagation delay CD to O LOW to HIGH Recovery times CD to I0, I1 Retrigger times O, O to I0, I1 LOW to OFF Minimum output pulse width LOW I0 Minimum output pulse width LOW I1 Output pulse width O, O VDD (V) 5 10 15 5 10 15 5 10 15 5 10 15 5 10 15 5 10 15 5 10 15 5 10 15 5 10 15 tWO tWI1H tWIOL tRO tRCD tPLH tPHL tPLH tPHL SYMBOL MIN. - - - - - - - - - - - - - - - 0 0 0 90 30 24 50 24 20 9.3 9.2 9.1 TYP. 200 90 60 220 85 60 125 55 40 125 55 40 20 10 5 - - - 45 15 12 25 12 10 10.0 9.9 9.8 MAX. 460 180 120 440 190 120 250 110 80 250 110 80 40 20 10 - - - - - - - - - 10.6 10.5 10.4 ms ns ns ns ns ns ns ns ns UNIT
HEF4938B
TYPICAL EXTRAPOLATION FORMULA 173 ns + (0.55 ns/pF) CL 79 ns + (0.23 ns/pF) CL 52 ns + (0.16 ns/pF) CL 193 ns + (0.55 ns/pF) CL 74 ns + (0.23 ns/pF) CL 52 ns + (0.16 ns/pF) CL 98 ns + (0.55 ns/pF) CL 44 ns + (0.23 ns/pF) CL 32 ns + (0.16 ns/pF) CL 98 ns + (0.55 ns/pF) CL 44 ns + (0.23 ns/pF) CL 32 ns + (0.16 ns/pF) CL
Rt = 100 k; Ct = 100 nF
January 1995
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Philips Semiconductors
Preliminary specification
Dual precision monostable multivibrator
AC CHARACTERISTICS VSS = 0 V; Tamb = 25 °C; CL = 50 pF; input transition times 20 ns VDD V Change in output O pulse width over temperature (Tamb) Change in output O pulse width over VDD range 5 to 15 V Pulse width variation between circuits in same package External timing resistor External timing capacitor Input capacitance (pin 2 or 14) Note CIN 15 pF Ct 2000 - no limits pF Rt 5 -
(1)
HEF4938B
SYMBOL
MIN.
TYP. ± 0,2
MAX. % % % % % % % k Rt = 100 k Ct = 2 nF to 10 µF
5 10 15 tWO 5 10 15 tWO tWO
± 0,2 ± 0,2 ± 1,5 ±1 ±1 ±1
1. The maximum permissible resistance Rt, which holds the specified accuracy of tWO, depends on the leakage current of the capacitor Ct and the leakage of the HEF4538B.
January 1995
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Philips Semiconductors
Preliminary specification
Dual precision monostable multivibrator
HEF4938B
Fig.5 Waveforms showing minimum I0, I1, O and CD pulse widths, recovery times and propagation delays.
January 1995
7
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(1) (2) (3) (4) (5) Positive edge triggering. Positive edge re-triggering (pulse lengthening). Negative edge triggering. Reset (pulse shortening). T = Rt × Ct.
Philips Semiconductors
Dual precision monostable multivibrator
Fig.6 Timing diagram.
Preliminary specification
HEF4938B