ROHM BA9700AFV, BA9700AF, BA9700A Datasheet
BA9700A / BA9700AF / BA9700AFV
Regulator ICs
Switching regulator for DC / DC
Converters
BA9700A / BA9700AF / BA9700AFV
The BA9700A, BA9700AF and BA9700AFV are switching regulators that use a pulse width modulation (PWM) system.
They use a transistor switch to stabilize the output voltage.
By the use of the transistor, power loss is decreased, fluctuation efficiency is improved, and the circuit is made more
compact and single.
Features
!!!!
1) Output voltage can step up, step down, or invert at an
arbitrary level.
2) Low current consumption. (typically 1.7mA)
3) Wide oscillation frequency range.
(typically 2.8k ~ 470kHz)
4) Built-in reference voltage current. (typically 2.57V)
5) Operates at low voltage. (minimally 3.55V)
6) Dead time controller restricts operation when
overloaded.
7) Power switch can isolate all circuits in the IC.
8) Best suited for battery operated equipment.
9) Compact 14-pin SSOP package (BA9700AFV).
Block diagram
!!!!
NON
INVERT
1/2 V
INPUT
14 13 12 11 10 9 8
+ −
Error
Amp
Triangle
Oscillator
1234567
R
Absolute maximum ratings
!!!!
D - TIME
CONT
(Ta = 25°C)
Parameter Symbol Limits Unit
Power supply voltage
CC
V
BA9700A
Power
dissipation
BA9700AF 350
Pd
BA9700AFV 350
Operating temperature
Storage temperature
1 BA9700A: Reduced by 4.8 mW for each increase in Ta of
*
2 BA9700AF: Reduced by 4.4 mW for each increase in Ta of
*
3 BA9700AFV : Reduced by 3.5 mW for each increase in Ta of
*
3 When mounted on a 5.0´5.0´1.6 mm glass epoxy board.
*2,*
Topr -20~+80 °C
Tstg -55~+150 °C
INVERT
ref
INPUT
T
1˚C over 25˚C.
1˚C over 25˚C.
1˚C over 25˚C.
POWER
SW
V
ref
30k
30k
PWM
Comparator
T
FEED
BACK
ref
V
24 V
1
*
600
2
*
3
*
Voltage
Regulator
mW
N. C.
BA9700A
BA9700AF
N. C.OUTC
V
GND
CC
Regulator ICs
Electrical characteristics
!
BA9700A / BA9700AF / BA9700AFV
(unless otherwise noted, Ta = 25°C, VCC = 5.0V, Rt = 10kΩ, and Ct = 330pF)
Parameter Min. Typ. Max. Unit Conditions
〈Reference voltage section〉
Output voltage
ref
1/2 V output voltage
Line regulation
Load regulation 1
Load regulation 2
Output voltage when power decreases
Output current when short-circuited
〈Triangular wave oscillation section〉
Oscillation frequency
Standard deviation of
oscillation frequency
Frequency variation (V )
〈Error amplifier section〉
CC
Input offset voltage
Input offset current
Maximum input voltage
Open loop gain
Common-mode rejection ratio
Input bias current
〈PWM comparator section〉
Threshold voltage 1
Threshold voltage 2
〈Output section〉
Output transistor leakage current
Output saturation voltage
〈Total device〉
Quiescent current
Standby current
Operating voltage
Symbol
V
ref
1/2 V
Line
Load1
Load2
ref
V
Iosc
fosc
fosc
fdv
IO
V
I
IO
V
ICR
A
V
CMRR
IB
I
V
t0
V
t100
Leak
Vsat
CC
I
I
CCS
V
CC
2.48 2.57 2.66 V I
ref
1.22 1.29 1.36 V
- 3.00 12.0 mV V
- 1.00 5.00 mV I
- 6.00 10.0 mV I
2.48 2.57 2.66 V
- 10.0 30.0 mA V
- 230 - kHz
-10-%
-1-%
-6.0 - mV
-100 - nA
6.0
100
1.60 1.90 - V
70.0 80.0 - dB
70.0 80.0 - dB
- 180 500 nA
- 2.04 2.24 V
1.25 1.43 - V
- - 10.0 µA
- 1.70 2.10 V
- 1.70 2.40 mA
- 0 7.00 µA
3.55 - 24.0 V
ref
= 0.1mA
CC
= 3.55V~24V
ref
= 0.1mA~1.0mA
ref
= 0.1mA~8.0mA
I
ref
= 0.1mA, VCC = 3.55V
ref
= 0V
T
= 10kΩ, CT = 330pF
R
T
R and C are constant
V
T
CC
= 3.55~24V
Null Method
Null Method
Null Method
Null Method
Null Method
Null Method
DUTY 0%
DUTY 100%
V
O
= 24V
I
O
= 50mA
T
= OPEN POWER SW = 2.5V
R
POWER SW = 0V
Regulator ICs
Timing chart
!!!!
ERR. AMP
OUTPUT
DEAD - TIME
PWM. COMP
OUTPUT
BA9700A / BA9700AF / BA9700AFV
H
L
OUTPUT TR.
COLLECTOR
Application examples
!!!!
V
GND
R
1
43k
1
C
7.5k
680p
R
3
C
2
0.047µ
15k
2
R
H
L
Fig.1
L
6
120µH
RB100A
D
1
1
N.C.
N.C.
Q12SB1009
C
8
7
R
560
R
560
IN
2.57V
11
30k
13
1.29V
30k
14
12
4
Voltage
Regulator
ERROR AMP
+
−
47k
SW
9
R
V
ref
C
1
PWM COMPARATOR
9
1000p
3108
Triangle
Oscillator
R815k
470µ
2
9
6
5
C5, C
470µF
×
5V
OUT
V
6
2
GND
17
C4 1µ
+
5
4
15k
20kR
R
Fig.2 Step-down converter
L1: RCH-875 121K (Sumida Electronics)
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