Datasheet

UNISONIC TECHNOLOGIES CO., LTD
BA9741
LINEAR INTEGRATED CIRCUIT
TWO-CHANNEL SWITCHING
REGULATOR CONTORLLER

DESCRIPTION
The UTC BA9741 is a two-channel switching regulator
controllers that use the PWM method.
It can be used for DC to DC conversion for step-up,
step-down, and inverting. The IC comes in a compact package,
making it ideal for use in portable equipment.

FEATURES
*High-accuracy reference voltage circuit (±1%)
*Time-latch, short-circuit protection circuit
*Miss-operation prevention circuit for low-voltage input
*Reference voltage with output (2.5V)
*Rest period adjustment is possible over the entire duty *range

ORDERING INFORMATION
Ordering Number
Lead Free
BA9741L-D16-T
-

Halogen Free
BA9741G-D16-T
BA9741G-S16-R
BA9741G-P16-R
Package
Packing
DIP-16
SOP-16
TSSOP-16
Tube
Tape Reel
Tape Reel
MARKING
DIP-16
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SOP-16 / TSSOP-16
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QW-R103-017.C
BA9741
LINEAR INTEGRATED CIRCUIT

PIN CONFIGURATIONS

PIN DESCRIPTIONS
PIN NO.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
PIN NAME
CT
RT
NON1
INV1
FB1
DT1
OUT1
GND
VCC
OUT2
DT2
FB2
INV2
NON2
SCP
VREF
FUNCTOIN
External timing capacitor
External timing resistor
Positive input for error amplifier 1
Negative input for error amplifier 1
Error amplifier 1 output
Output 1 dead time/soft start setting
Output 1
Ground
Power supply
Output 2
Output 2 dead time / soft start setting
Error amplifier 2 output
Negative input for error amplifier 2
Positive input for error amplifier 2
Time latch setting
Reference voltage output (2.5V)
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BA9741

LINEAR INTEGRATED CIRCUIT
BLOCK DIAGRAM
VREF 16
Vref
NON 1 3
+
INV 1 4
-
FB 1 5
NON 2 14
+
INV 2 13
-
FB 2 12
RT
2
CT
1
VCC
9
Reference
Voltage
Triangle
Oscillator
7 OUT1
+
+
-
Err
Amp 1
+
+
SCP Comp
Err
Amp 2
Vref
Vref
+
+
PWM
Comp1
10 OUT2
PWM
Comp2
Vref
SCP 15
STimeR
r
Latch
R
UVL
O
6 11
DT1 DT2
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8
GND
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BA9741

LINEAR INTEGRATED CIRCUIT
ABSOLUTE MAXIMUM RATINGS (TA=25C, unless otherwise specified)
PARAMETER
SYMBOL
RATINGS
UNIT
Power Supply Voltage
VCC
36
V
Output Current
IO
120(note 2)
mA
Output Voltage
VO
36
V
Power Dissipation (Note 2)
SOP-16
PD
500
mW
DIP-16
650
Operating Temperature
TOPR
-40 ~ +85
C
Storage Temperature
TSTG
-55 ~ +125
C
Notes: 1. Absolute maximum ratings are those values beyond which the device could be permanently damaged.
Absolute maximum ratings are stress ratings only and functional device operation is not implied.
2. When mounted on 70mm×70mm×1.6mm glass epoxy board.
Reduced by 5.0mW, for each increase in TA of 1C over 25C.
3. Should not exceed Pd and ASO values.

RECOMMENDED OPERATING CONDITIONS (TA=25C, unless otherwise specified)
PARAMETER
Power Supply Voltage
Output Current
Output Voltage
Error Amplifier Input Voltage
Timing Capacitor
Timing Resistor
Oscillator Frequency
SYMBOL
VCC
IO
VO
VOM
CCT
RRT
FOSC
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MIN
3.6
0.3
100
5.1
10
TYP
6.0
MAX
35
100
35
1.6
15000
50
800
UNIT
V
mA
V
V
pF
k
kHz
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BA9741
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LINEAR INTEGRATED CIRCUIT
ELECTRICAL CHARACTERISTICS (TA=25C, VCC=6V, unless otherwise specified)
PARAMETER
SYMBOL
TEST CONIDITIONS
REFERENCE VOLTAGE BLOCK
Output Voltage
VREF
IREF =1mA
Input Stability
VDLI
VCC =3.6~35V
Load Stability
VDLO
IREF =0~5mA
TRIANGULAR WAVE OSCILLATOR
Oscillation Frequency
FOSC
RRT=10 kΩ, CCT=220pF
Frequency Deviation
FDV
VCC=3.6~35V
PROTECTION CIRCUIT
Threshold Voltage
VIT
Standby Voltage
VSTB
No pull up
Latch Voltage
VLT
No pull up
Source Current
ISCP
Comparator Threshold Voltage
VCT
5Pin,12Pin
REST PERIOD ADJUSTMENT CIRCUIT
Input Threshold Voltage
Vt0
Duty Cycle =0%
(fosc=10kHz)
Vt100
Duty Cycle =100%
On Duty Cycle
DON
Divide VREF using 13 kΩ and27 kΩ
Input Bias Current
IBDT
DT1, DT2=2.0V
Latch Mode Source Current
IDT
DT1, DT2=0V
Latch Input Voltage
VDT
IDT=40µA
LOW-VOLTAGE INPUT MISS-OPERATION PREVENTION CIRCUIT
Threshold Voltage
VUT
ERROR AMPLIFIER
Input Offset Voltage
VIO
Input Offset Current
IIO
Input Bias Current
IIB
Open Circuit Gain
AV
Common-mode Input Voltage range
VOM
VCC=3.6~35V
Common-mode Rejection Ratio
CMRR
Maximum Output Voltage
VOH
Minimum Input Voltage
VOL
Output Sink Current
IOI
FB=1.25V
Output Source Current
IOO
FB=1.25V
PWM COMPARATOR
Input Threshold Voltage
Vt0
Duty Cycle =0%
(fosc=10kHz)
Vt100
Duty Cycle =100%
OUTPUT BLOCK
Saturation Voltage
VSAT
IO=75mA
Leak Current
IREAK
VO=35V
TOTAL DEVICE
Standby Current
ICCS
When output is off
Average Current Consumption
ICCA
RRT=10 kΩ
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MIN
TYP. MAX
UNIT
2.4
2.5
1
1
2.6
10
10
V
mV
mV
320
400
1
480
kHz
%
1.48
1.64
50
30
2.5
1.05
1.80
100
100
3.5
1.2
V
mV
mV
µA
V
1.97
1.48
55
0.1
560
2.48
2.15
1.64
65
1
V
V
%
µA
µA
V
1.5
0.9
1.79
1.32
45
200
2.28
2.53
70
0.3
60
2.3
15
85
V
6
30
100
1.6
mV
nA
nA
dB
V
dB
V
V
mA
µA
0.9
3
45
80
2.5
0.7
20
75
1.79
1.32
1.97
1.48
2.15
1.64
V
V
0.8
0
1.2
5
V
µA
1.3
1.6
1.8
2.3
mA
mA
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BA9741

LINEAR INTEGRATED CIRCUIT
TIMING CHART
Triangular wave output(from oscillator)
Error amplifier output
Dead-time input voltage
1.97V
1.05V
Short protection comparator
1.48V
PWM comparator output
Output waveform
1.64V
SCP waveform
tDT
Short protection comparator
output
VCC = 3.6V
2.53V
Lockout release
Power supply voltage
Figure. 1
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BA9741
ELECTRICAL CHARACTERISTIC CURVES
1.0
0.5
0
-0.5
-1.0
2.0
VCC =6V
RT1=10KΩ
Upper Voltage
1.8
1.6
Lower Voltage
1.4
-1.5
-20
0
20 40 60 80
Ambient Temperature, TA (°C)
1.2
10K
100
Figure4. Output Current vs.Output
Saturation Voltage
Av
40
180
30
0.8
0.6
0.4
20
90
10
0
θ
0
-10
-20
-90
-30
0.2
0
0
1M
Figure 5. Error Amplifier AC Gain
Characteristic (40dB close)
50
1.0
100K
Oscillator Frequency, fOSC (Hz)
Phase, θ(deg)
-2.0
-40
1.2
Output Saturation Voltage, VOSAT (V)
VCC=6V
IREF = -1mA
1.5
Figure 3. Swing Voltage vs. Frequency
2.2
Swing Voltage, VOSC (V)
2.0
Figure 2. Reference Voltage vs.Ambient
Temperature
Gain, Av (dB)
Reference Voltage Variation, ?VREF (%)

LINEAR INTEGRATED CIRCUIT
20
40
60
80
100 120 140
Output Current, IO (mA)
-40
-50
100
-180
1K
10K
100K
1M
Frequency, f (Hz)
UTC assumes no responsibility for equipment failures that result from using products at values that
exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or
other parameters) listed in products specifications of any and all UTC products described or contained
herein. UTC products are not designed for use in life support appliances, devices or systems where
malfunction of these products can be reasonably expected to result in personal injury. Reproduction in
whole or in part is prohibited without the prior written consent of the copyright owner. The information
presented in this document does not form part of any quotation or contract, is believed to be accurate
and reliable and may be changed without notice.
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