Standard ICs CR timer BA225 / BA225F / 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 •Delay timers Monostable multivibrator (ideal for VCR system controllers) Pulse generators •1)Features As these are edge trigger types (BA225 / BA235: ris- 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. ing 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. •Block diagram BA225 / BA225F BA235 / BA236 BA226 / BA226F OUT1 1 8 VCC 7 OUT2 6 CR2 5 TRIGGER2 O CR1 2 CR O T T CR O CR O T 2 3 4 5 6 7 8 9 GND TRIGGER2 CR2 OUT2 VCC 4 VCC 1 TRIGGER1 T GND GND VCC CR1 CR OUT1 3 VCC TRIGGER1 1 Standard ICs BA225 / BA225F / BA235 / BA226 / BA226F / BA236 •Absolute maximum ratings (Ta = 25°C) Parameter Symbol Power supply voltage Limits VCC 16 BA225 / BA226 Power dissipation BA235 / BA236 Unit Pd BA225F / BA226F V 800∗1 mW 950∗2 mW 450∗3 mW Operating temperature Topr – 20 ~ + 75 °C Storage temperature Tstg – 55 ~ + 125 °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 CC Parameter Symbol Min. Operating power supply voltage Typ. Max. = 5V) Unit Conditions Measurement circuit — Fig.7 VCC 4.0 5.0 16.0 V Quiescent current IQ — 1.5 3.0 mA Timing accuracy TERR — 1 10 % R = 100kΩ, C = 0.1µF∗1 Fig.7 5V➝16V Fig.7 — Timing change with power supply TDS — 0.5 3.0 % Timing change with temperature TOT — 200 — ppm / °C Trigger voltage VT 1.0 2.0 3.0 0.7 1.6 2.5 IT — 70 200 Output low level voltage VOL — 0.5 Output high level voltage VOH 3.0 4.0 BA236 Trigger current Fig.7 — Fig.7 ∗2 Fig.7 µA VT = 3.0V (BA225 / BA235) VT = 2.5V (BA226 / BA226F / BA236) Fig.7 1.0 V ISINK = 5mA Fig.7 — V ISOURCE = 5mA Fig.7 V ∗1 One-shot cycle T = 0.5 CR ∗2 With input hysteresis (hysteresis width ⱌ 200 to 600mV) 2.0 3 "H" output 2 "L" output 1 0 0 4 8 12 16 20 POWER SUPPLY VOLTAGE: VCC (V) Fig. 1 Quiescent current vs. power supply voltage 2 VCC = 5V VCC = 5V SATURATION VOLTAGE: VOL (V) 4 SATURATION VOLTAGE: VCC—VOH (V) QUIESCENT CURRENT: IO (mA) •Electrical characteristic curves 3.2 2.8 2.4 2.0 1.6 1.2 0.8 0.4 0 0 4 8 12 16 SOURCE CURRENT: ISOURCE (mA) Fig. 2 Output voltage (logic 1 side) characteristics 20 1.0 0 0 4 8 12 16 SINK CURRENT: ISINK (mA) Fig. 3 Output voltage (logic 0 side) characteristics 20 BA225 / BA225F / BA235 / BA226 / BA226F / BA236 0.990 0.985 1.000 0.995 0.990 0.985 1.0 0.1 0.01 0.980 0.980 0 1.005 Ω 0.995 1.010 10 0k Ω 1.000 1.015 1M 1.005 10 CAPACITANCE: C (µF) 1.010 0 VCC = 5V C = 0.01µF R = 100kΩ 1.020 DELAY TIME NORMALIZED: td DELAY TIME NORMALIZED: td C = 0.01µF R = 100kΩ 10 kΩ Standard ICs 4 8 12 16 – 25 20 0 25 50 0.001 75 0.01 AMBIENT TEMPERATURE: Ta (°C) POWER SUPPLY VOLTAGE: VCC (V) 1 10 100 TIMING PERIOD: T (ms) Fig. 5 Temperature vs. delay time Fig. 4 Power supply voltage vs. delay time 0.1 Fig. 6 One-shot time characteristics •Measurement circuit S1 OFF VCC S0 mA ON VCC BA225 BA225F BA235 S2 IN D.V µA CR PG OUT GND 100kΩ S3 Counter D.V 5mA 5mA 0.1µF Fig. 7 components •(1)Attached 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 0.02µF capacitor between the power supply pin and the ground (GND) so as to prevent malfunction resulting from a rise in the impedance of the power supply line. (4) Load (Pins 1 and 7) A load of up to 5mA can be accommodated for both the inflow current and the outflow current. 3 BA225 / BA225F / BA235 / BA226 / BA226F / BA236 notes •(1)Operation Usage range for voltage The recommended voltage range is 4.0V to 16V. Use of these ICs at 3.0V or lower voltage may cause the same mode as the input trigger signal to be output at around 2.6V. (2) Input trigger The input trigger level is 2.0V. The LOW level is 1.0V or lower and the HIGH level is 3.0 V or higher. Trigger signals of 10ms / V or lower should be used for both the rising and falling edges. (3) Time constant determining C • R The recommended value for the timing capacitor is 1000pF or more and that for the timing resistor is from 10kΩ to 1MΩ. The voltage, which is determined by comparison of discharge resistance and the timing resistance in the IC, remains on the CR pins. If timing resistance is set at 5kΩ or less, this voltage will reach threshold level (0.4 × VCC), and operation will come to a halt. Also, when timing resistance is set to a low value, voltage remains on the CR pins, which shortens the time constant. If timing resistance is set to 2MΩ or higher, the IC's internal comparator cannot be driven, which may bring operation to a halt. (4) Note that pin connections and pin arrangements on the BA225 / BA226 (BA235F / BA226F) differ from those on the BA235 / BA236. Application example •Figure 8 shows an example of the circuit including these ICs, while Figure 9 shows the basic operation timing chart. Figure 10 shows the basic operation timing chart of the falling edge trigger type IC. When no trigger signal is applied, the output is in the LOW state and the timing capacitor is in the discharged state. When a trigger signal is applied, its rising edge causes the output to become HIGH and the timing capacitor to be charged. The charging time of this timing capacitor is determined by the time constants of the external timing resistor and the timing capacitor. When the charged voltage reaches 0.4 × VCC, the flip-flop in the IC is reset and the output state changes from HIGH to LOW. At the same time, the timing capacitor is discharged to be ready for the next operation. VCC VCC = 5V R 100kΩ OUT2 0.02µF 0.1µF Standard ICs 8 7 C 6 5 VCC CR 0 T M. M2 BA225 BA226 BA225F BA226F M. M1 0 T CR GND 1 2 3 4 OUT1 100kΩ R VCC 0.1µF C Fig. 8 4 Standard ICs BA225 / BA225F / BA235 / BA226 / BA226F / BA236 •Application examples Rising edge trigger Trigger input 0.4VCC CR pin T Output One-shot cycle: T ⱌ 0.5 CR Fig. 9 Basic operation timing chart (Rising edge trigger) Falling edge trigger Trigger input 0.4VCC CR pin T Output One-shot cycle: T ⱌ 0.5 CR Fig. 10 Basic operation timing chart (Falling edge trigger) 5 Standard ICs BA225 / BA225F / BA235 / BA226 / BA226F / BA236 •External dimensions (Units: mm) BA225 / BA226 BA235 / BA236 0.3 ± 0.1 SIP9 1 4 0.11 0.15 ± 0.1 4.4 ± 0.2 5 1.5 ± 0.1 6.2 ± 0.3 5.0 ± 0.2 8 0.4 ± 0.1 0.3Min. 0.15 SOP8 0.6 0.8 0.5 ± 0.1 0° ~ 15° 2.54 BA225F / BA226F 6 9 2.54 1.3 DIP8 1.27 1 3.5 ± 0.5 7.62 2.8 ± 0.2 1.2 4 5.8 ± 0.2 1 21.8 ± 0.2 10.5 ± 0.5 5 6.5 ± 0.3 8 0.51Min. 3.2 ± 0.2 3.4 ± 0.3 9.3 ± 0.3 0.3 ± 0.1