Document
Standard ICs
CR timer
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BA225 / BA225F U / BA235 / BA226 / BA226F / BA236
The BA225, BA225F, BA235, BA226, BA226F, and BA236 are monolithic ICs having independent monostable multivibrator circuits which consume very low current (0.75mA typ.). Using external resistors and capacitors, the timing control time can be set within a range from 0.01ms to 100ms. As the BA225, BA225F, and BA235 are triggered at the rising edge of the signal, they have no trigger input differentiating circuit and can be used in measuring instruments, control devices, digital data systems and other equipment as sub-compact attachments. The BA226, BA226F, and BA236 are available as falling edge trigger types. Applications • w Delay timers Monostable multivibrator (ideal for VCR system controllers) Pulse generators Features • 1) As these are edge trigger types (BA225 / BA235: rising edge trigger types, BA226 / BA236: falling edge trigger types), there is no need for an input differentiating circuit. 2) The dual type design enables delay timer configuration. 3) Fewer attachments are required. 4) Current dissipation is as low as 0.75mA for each circuit.
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•Block diagram
BA225 / BA225F BA226 / BA226F
OUT1
CR1
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1 2 3 4
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O CR T
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O T
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8 7 6 5
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5) Uniformity in the supply current between high and low output states simplifies the design of the power supply section. 6) Wide operating power supply voltage range of 4.0V to 16V. 7) The BA235 and BA236 pin assignments are symmetrical, allowing reverse insertion. 8) Hysteresis in the input results in a high level of noise withstand resistance.
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BA235 / BA236
VCC
OUT2
O CR VCC
T GND
TRIGGER1
CR
CR2
1 VCC
2 OUT1
3 CR1
4 TRIGGER1
TRIGGER2
GND
TRIGGER2
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OUT2
GND
CR2
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CR VCC 8 9 VCC
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Standard ICs
BA225 / BA225F / BA235 / BA226 / BA226F / BA236
•Absolute maximum ratings (Ta = 25°C)
Parameter Power supply voltage BA225 / BA226 Power dissipation BA235 / BA236 BA225F / BA226F Operating temperature Storage temperature Topr Tstg Pd Symbol VCC Limits 16 800∗1 950∗2 450∗3 – 20 ~ + 75 – 55 ~ + 125 Unit V mW mW mW °C °C
∗1 Reduced by 8mW for each increase in Ta of 1°C over 25°C. ∗2 Reduced by 9.5mW for each increase in Ta of 1°C over 25°C. ∗3 Reduced by 4.5mW for each increase in Ta of 1°C over 25°C.
•Electrical characteristics (unless otherwise noted, Ta = 25°C, V
Parameter Operating power supply voltage Quiescent current Timing accuracy Timing change with power supply Timing change with temperature Trigger voltage Symbol Min. VCC IQ TERR TDS TOT VT 4.0 — — — — 1.0 0.7 — — 3.0 Typ. Max. 5.0 1.5 1 0.5 200 2.0 1.6 70 0.5 4.0 16.0 3.0 10 3.0 — 3.0 2.5 200 1.0 —
CC
= 5V)
Conditions — — R = 100kΩ, C = 0.1µF∗1 5V¨16V —
∗2
Unit V mA % % ppm / °C V µA V V
Measurement circuit Fig.7 Fig.7 Fig.7 Fig.7 Fig.7 Fig.7
BA236
Trigger current Output low level voltage Output high level voltage
IT VOL VOH
VT = 3.0V (BA225 / BA235) VT = 2.5V (BA226 / BA226F / BA236) ISINK = 5mA ISOURCE = 5mA
Fig.7 Fig.7 Fig.7
∗1 One-shot cycle T = 0.5 CR
∗2 With input hysteresis (hysteresis width Լ 200 to 600mV)
•Electrical characteristic curves
SATURATION VOLTAGE: VCC—VOH (V) VCC = 5V 3.2 2.8 2.4 2.0 1.6 1.2 0.8 0.4 0 0 4 8 12 16 20 SATURATION VOLTAGE: VOL (V) QUIESCENT CURRENT: IO (mA) 4 3 "H" output 2 "L" output
2.0 VCC = 5V
1.0
1
0 0
4
8
12
16
20
0 0
4
8
12
16
20
POWER SUPPLY VOLTAGE: VCC (V)
SOURCE CURRENT: ISOURCE (mA)
SINK CURRENT: ISINK (mA)
Fig. 1 Quiescent current vs. power supply voltage
Fig. 2 Output voltage (logic 1 side) characteristics
Fig. 3 Output voltage (logic 0 side) characteristics
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Standard ICs
BA225 / BA225F / BA235 / BA226 / BA226F / BA236
C = 0.01µF R = 100kΩ DELAY TIME NORMALIZED: td DELAY TIME NORMALIZED: td
1.020 1.015 1.010 1.005 1.000 0.995 0.990 0.985 0.980
VCC = 5V C = 0.01µF R = 100kΩ CAPACITANCE: C (µF)
10
1.010 1.005 1.000 0.995 0.990 0.985 0.980 0 0 4 8 12 16 20
1.0
10 kΩ
0.1
10 0k Ω
0.01
– 25
0
25
50
75
0.001 0.01 0.1 1 10 100 TIMING PERIOD: T (ms)
POWER SUPPLY VOLTAGE: VCC (V)
AMBIENT TEMPERATURE: Ta (°C)
Fig. 4 Power supply voltage vs. delay time
Fig. 5 Temperature vs. delay time
Fig. 6 One-shot time characteristics
•Measurement circuit
S1 OFF S0 mA ON VCC VCC
S2 IN D.V µA PG 100kΩ
BA225 BA225F BA235
CR GND
OUT
S3 Counter 5mA 5mA
D.V
0.1µF
Fig. 7
Attached components • (1) Timing capacitors (Pins 2 and 6) Connected between these pins and the ground (GND), this capacitor determines the one-shot period. We recommend using a capacitor with a value greater than 1000pF. The one-shot cycle is determined by T = 1 / 2 C • R. (2) Timing resistor (Pins 2 and 6) Connected to the power supply line, these resistors determine the one-shot period. The timing capacitor is charged through this resistor. The recommended range for the timing resistor is 10kΩ to 1MΩ.
(3) Power supply capacitor (Pin 8) Connect a 0..