Rohm BA235 Cr timer Datasheet

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