ROHM BA9700AF

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
INPUT
1/2 Vref
INVERT
INPUT
Vref
POWER
SW
N. C.
VCC
14
13
12
11
10
9
8
+ −
Voltage
Regulator
30k
Error
Amp
30k
Vref
BA9700A
BA9700AF
PWM
Comparator
Triangle
Oscillator
1
2
3
D - TIME
CONT
RT
CT
4
FEED
BACK
5
6
7
OUT
N. C.
GND
!Absolute maximum ratings (Ta = 25°C)
Parameter
Power supply voltage
Symbol
Limits
Unit
VCC
24
V
600 *1
BA9700A
Power
dissipation
BA9700AF
Pd
350 *2
mW
350 *3
BA9700AFV
Operating temperature
Topr
-20~+80
°C
Storage temperature
Tstg
-55~+150
°C
*1 BA9700A: Reduced by 4.8 mW for each increase in Ta of 1˚C over 25˚C.
*2 BA9700AF: Reduced by 4.4 mW for each increase in Ta of 1˚C over 25˚C.
*3 BA9700AFV : Reduced by 3.5 mW for each increase in Ta of 1˚C over 25˚C.
*2,*3 When mounted on a 5.0´5.0´1.6 mm glass epoxy board.
BA9700A / BA9700AF / BA9700AFV
Regulator ICs
!Electrical characteristics (unless otherwise noted, Ta = 25°C, VCC = 5.0V, Rt = 10kΩ, and Ct = 330pF)
Parameter
Symbol
Min.
Typ.
Max.
Unit
Conditions
〈Reference voltage section〉
Output voltage
1/2 Vref output voltage
Vref
2.48
2.57
2.66
V
1/2 Vref
1.22
1.29
1.36
V
Iref = 0.1mA
Line
-
3.00
12.0
mV
VCC = 3.55V~24V
Load regulation 1
Load1
-
1.00
5.00
mV
Iref = 0.1mA~1.0mA
Load regulation 2
Iref = 0.1mA~8.0mA
Line regulation
Load2
-
6.00
10.0
mV
Output voltage when power decreases
Vref
2.48
2.57
2.66
V
Output current when short-circuited
Iosc
-
10.0
30.0
mA
Vref = 0V
Oscillation frequency
fosc
-
230
-
kHz
RT = 10kΩ, CT = 330pF
Standard deviation of
oscillation frequency
fosc
-
10
-
%
RT and CT are constant
Frequency variation (VCC )
fdv
-
1
-
%
VCC = 3.55~24V
VIO
-6.0
-
6.0
mV
Null Method
Iref = 0.1mA, VCC = 3.55V
〈Triangular wave oscillation section〉
〈Error amplifier section〉
Input offset voltage
IIO
-100
-
100
nA
Null Method
VICR
1.60
1.90
-
V
Null Method
AV
70.0
80.0
-
dB
Null Method
CMRR
70.0
80.0
-
dB
Null Method
IIB
-
180
500
nA
Null Method
Threshold voltage 1
Vt0
-
2.04
2.24
V
DUTY 0%
Threshold voltage 2
Vt100
1.25
1.43
-
V
DUTY 100%
Output transistor leakage current
Leak
-
-
10.0
µA
VO = 24V
Output saturation voltage
Vsat
-
1.70
2.10
V
IO = 50mA
Quiescent current
ICC
-
1.70
2.40
mA
RT = OPEN POWER SW = 2.5V
Standby current
ICCS
-
0
7.00
µA
POWER SW = 0V
Operating voltage
VCC
3.55
-
24.0
V
Input offset current
Maximum input voltage
Open loop gain
Common-mode rejection ratio
Input bias current
〈PWM comparator section〉
〈Output section〉
〈Total device〉
BA9700A / BA9700AF / BA9700AFV
Regulator ICs
!Timing chart
ERR. AMP
OUTPUT
DEAD - TIME
H
PWM. COMP
OUTPUT
L
H
OUTPUT TR.
COLLECTOR
L
Fig.1
!Application examples
L1
Q1 2SB1009
VIN
R9
GND
C9 1000p
SW1
R8 15k
C8
470µ
47k
RB100A
8
11
2.57V
10
3
Voltage
Regulator
5V
VOUT
120µH
R7
560
2
C5, C6
470µF
×2
D1
Triangle
Oscillator
GND
30k
Vref
13
9
N.C.
6
N.C.
30k
R1
43k
ERROR AMP
14
R2
15k
1.29V
C1
680p
R3
7.5k
R6
560
+
−
12
PWM COMPARATOR
5
C2
4
0.047µ
7
C4 1µ
1
+
L1: RCH-875 121K (Sumida Electronics)
R4 15k
R5 20k
Fig.2 Step-down converter
BA9700A / BA9700AF / BA9700AFV
Regulator ICs
Q1 2SB1009
VIN
RB100A
VOUT
R9
GND
SW1
D1
R8 10k
47k
2.57V
330
R7
C6
470µ
8
11
C7 1000p
10
3
Voltage
Regulator
L1
220µH
2
C4, C5
470µ
×2
Triangle
Oscillator
GND
30k
Vref
13
ERROR AMP
14
R3
6.8k
9
1.29V
330
R6
30k
R1
33k
−
C1
R2
6
+
12
7.5k
5
PWM COMPARATOR
680p
4
0.047µ
C2
7
C3 1µ
1
L1: RCH-875 220K (Sumida Electronics)
R5 39k
R4 22k
Fig.3 Inverting converter
L1
RB100A
VIN
R11
GND
C8 1000p
SW1
22µH
R1010k
C7
100µ
47k
8
10
3
R9
470
C5, C6
470µ
×2
2
Q1
11
2.57V
Voltage
Regulator
2SB1009
Triangle
Oscillator
R8 68
30k
9
1.29V
R7
470
30k
R1
39k
ERROR AMP
14
R2
4.7k
Q2
2SD1380
Vref
13
12V
VOUT
D1
6
GND
R6
470
+
−
R3
7.5k
12
C2
PWM COMPARATOR
C1
680p
5
4
0.047µ
7
C4 1µ
1
L1: RCH-875 221K (Sumida Electronics)
R4 20k
R5 39k
Fig.4 Step-up converter
BA9700A / BA9700AF / BA9700AFV
Regulator ICs
!Basic application board patterns and component arrangemrnts
R5
R8
C9
R2
R6
( )+ ( )+
R1
R9
VIN
C4
R4
C11
C3
C1
BA9700A
R3
C10
C2
C5
VOUT
+
L
Q1
B
GND
SW
C
R7
+
GND
E
C8
C6
+
D
C7
BA9700A - 1
Fig.5 Step-down converter
C7
C1
BA9700A
R6
SW
R3
VOUT
C4
+
R1
C5
R9
GND
R5
R4
R2
VIN
R8
C3
C2
L
+
Q1
B
+
GND
C
D1
E
C6
BA9700A - 2
Fig.6 Inverting converter (BA9700A)
C4
C3
R5
R10
C2
R4
R3
R6
C1
BA9700A
Q2
B
R7
C7
Fig.7 Step-up converter (BA9700A)
Q1
R9
+
VOUT
R8
R11
SW
GND
C6
R2 +
R1
VIN
+
GND
B
C
C
E
E
L
C5
BA9700A / BA9700AF / BA9700AFV
Regulator ICs
!Electrical characteristic curves
1M
4.00
1M
3.50
R
CT = 2200pF
10k
CT = 0.022µF
1k
T
=
3.00
10
kΩ
=
RT = 20kΩ
30
kΩ
10k
Vref (VOLTAGE)
T
100k
FREQUENCY
FREQUENCY (Hz)
R
(Hz)
CT = 220pF
100k
2.50
2.00
1.50
1.00
1k
0.50
1k
10k
100k
100p
1M
Oscillation frequency
characteristic vs. triangular
wave oscillator resistance (1)
Fig.9
200
100
(d B)
60
40
GA I N
PHASE (DEG)
80
300
20
0
0
-100
-20
-200
-40
0
100
1k
10k
100k
1M
FREQUENCY (Hz)
Fig.11
0.01µ
0.1µ
0.00
Phase and gain vs. frequency
for the error amplifier
10M
Oscillation frequency
characteristic vs. triangular
wave oscillator resistance (2)
5
10
15
20
25
VCC (V)
CT (F)
RT (Ω)
Fig.8
1000p
Fig.10
Output voltage vs. operating
voltage for the reference
voltage section
BA9700A / BA9700AF / BA9700AFV
Regulator ICs
!External dimensions (Units : mm)
BA9700A
BA9700AF
19.4±0.3
8.7±0.2
8
3.2±0.2
0.3±0.1
2.54
0.15±0.1
4.4±0.2
0.1
1.15±0.1
6.4±0.3
5.0±0.2
7
0.65
0.22±0.1
1.27
0.4±0.1
0.3Min.
SOP14
BA9700AFV
1
7
0.15
DIP14
8
1
0°∼15°
0.5±0.1
14
8
0.15±0.1
1.5±0.1
7.62
14
4.4±0.2
6.2±0.3
7
0.51Min.
4.25±0.3
1
0.11
6.5±0.3
14
0.3Min.
0.1
SSOP - B14