UTC-IC BA9741A

UTC BA9741A
LINEAR INTEGRATED CIRCUIT
TWO-CHANNEL SWITCHING
REGULATOR CONTORLLER
DESCRIPTION
The UTC BA9741A 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.
SOP-16
FEATURES
TSSOP-16
*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.
APPLICATION
DIP-16
*DC/DC converters for video cameras and notebook
computers etc.
PIN CONFIGURATIONS
CT
1
16
VREF
RT
2
15
SCP
NON1 3
ERROR
AMPLIFIER 1
INV1 4
UTC
14 NON2
13 INV2
FB1
5
12
FB2
DT1
6
11
DT2
OUT1
7
10
OUT2
GND
8
9
ERROR
AMPLIFIER 2
Vcc
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QW-R103-019,A
UTC BA9741A
LINEAR INTEGRATED CIRCUIT
PIN DESCRIPTIONS
PIN NO.
PIN NAME
1
CT
FUNCTOIN
External timing capacitor
External timing resistor
2
RT
3
NON1
Positive input for error amplifier 1
4
INV1
Negative input for error amplifier 1
5
FB1
Error amplifier 1 output
6
DT1
Output 1 dead time/soft start setting
7
OUT1
Output 1
8
GND
Ground
9
Vcc
Power supply
10
OUT2
11
DT2
Output 2 dead time / soft start setting
12
FB2
Error amplifier 2 output
13
INV2
Negative input for error amplifier 2
14
NON2
Positive input for error amplifier 2
15
SCP
16
VREF
Output 2
Time latch setting
Reference voltage output (2.5V)
BLOCK DIAGRAM
Vcc
9
VREF 16
Vref
RT
2
CT
1
Reference
Voltage
Triangle
Oscillator
7 OUT1
NON 1 3
+
INV 1 4
-
FB 1 5
NON 2 14
+
INV 2 13
-
FB 2 12
+
+
-
Err
Amp 1
+
+
SCP Comp
PWM Comp1
10 OUT2
Err
Amp 2
+
+
Vref
PWM Comp2
Vref
Vref
SCP 15
S
Timer
Latch
R
R
UVLO
6
11
DT1 DT2
UTC
8
GND
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QW-R103-019,A
UTC BA9741A
LINEAR INTEGRATED CIRCUIT
ABSOLUTE MAXIMUM RATINGS( Ta=25°C )
SYMBOL
VALUE
UNIT
Power Supply Voltage
PARAMETER
Vcc
36
V
Power Dissipation (note 1)
SOP-16
DIP-16
Pd
500
mW
650
Operating Temperature
Topr
Storage Temperature
°C
-40 to 85
Tstg
-55 to 125
°C
Output Current
Io
120(note 2)
mA
Output Voltage
Vo
36
V
Note 1: 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
Note 2: Should not exceed Pd and ASO values.
RECOMMENDED OPERATING CONDITIONS( Ta=25°C )
PARAMETER
Power Supply Voltage
Output Current
SYMBOL
MIN
TYP.
MAX
UNIT
Vcc
3.6
6.0
35
100
V
mA
35
V
1.6
15000
50
800
V
pF
kΩ
kHz
Io
Output Voltage
Vo
Error Amplifier Input Voltage
Timing Capacitor
Timing Resistor
Oscillator Frequency
VOM
CCT
RRT
FOSC
0.3
100
5.1
10
ELECTRICAL CHARACTERISTICS( TA=25°C ,VCC=6V,UNLESS OTHERWISE NOTED.)
PARAMETER
SYMBOL
TEST CONIDITIONS
MIN
TYP. MAX UNIT
REFERENCE VOLTAGE BLOCK
Output Voltage
Vref
Iref =1mA
2.5
2.6
V
Input Stability
VDLI
Vcc =3.6~35V
1
10
mV
Load Stability
VDLO
Iref =0~5mA
1
10
mV
TRIANGULAR WAVE OSCILLATOR
Oscillation Frequency
Fosc
RRT=10 kΩ ,CCT=220pF
400
480
kHz
Frequency Deviation
FDV
Vcc=3.6~35V
PROTECTION CIRCUIT
Threshold Voltage
Standby Voltage
VIT
No pull up
Latch Voltage
VLT
No pull up
Source Current
ISCP
Comparator Threshold Voltage
VCT
UTC
320
1
1.48
VSTB
REST PERIOD ADJUSTMENT CIRCUIT
Input Threshold Voltage
Vt0
(fosc=10kHz)
Vt100
2.4
%
1.64
1.80
V
50
100
mV
30
100
mV
1.5
2.5
3.5
µA
5Pin,12Pin
0.9
1.05
1.2
V
Duty Cycle =0%
1.79
1.97
2.15
V
Duty Cycle =100%
1.32
1.48
1.64
V
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QW-R103-019,A
UTC BA9741A
LINEAR INTEGRATED CIRCUIT
PARAMETER
SYMBOL
TEST CONIDITIONS
MIN
DON
Divide Vref using 13 kΩ and27 kΩ
45
IBDT
DT1,DT2=2.0V
TYP. MAX UNIT
On Duty Cycle
Input Bias Current
Latch Mode Source Current
IDT
DT1,DT2=0V
200
560
µA
VDT
IDT=40µA
2.28
2.48
V
2.53
V
Latch Input Voltage
LOW-VOLTAGE INPUT MISS-OPERATION PREVENTION CIRCUIT
Threshold Voltage
VUT
55
65
%
0.1
1
µA
ERROR AMPLIFIER
Input Offset Voltage
VIO
6
Input Offset Current
IIO
30
nA
Input Bias Current
IIB
100
nA
Open Circuit Gain
15
AV
Common-mode Input Voltage range
Common-mode Rejection Ratio
VOM
70
Vcc=3.6~35V
85
mV
dB
0.3
1.6
80
V
CMRR
60
dB
Maximum Output Voltage
VOH
2.3
Minimum Input Voltage
VOL
Output Sink Current
IOI
FB=1.25V
3
20
mA
Output Source Current
IOO
FB=1.25V
45
75
µA
PWM COMPARATOR
Input Threshold Voltage
(fosc=10kHz)
Vt0
Duty Cycle =0%
1.79
1.97
2.15
V
Vt100
Duty Cycle =100%
1.32
1.48
1.64
V
OUTPUT BLOCK
Saturation Voltage
VSAT
Io=75mA
0.8
1.2
V
Leak Current
IREAK
Vo=35V
0
5
µA
TOTAL DEVICE
Standby Current
Iccs
When output is off
1.3
1.8
mA
Average Current Consumption
IccA
RRT=10 kΩ
1.6
2.3
mA
2.5
V
0.7
0.9
V
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
2.53V
Vcc >
= 3.6V
Lockout release
Power supply voltage
Figure. 1
UTC
UNISONIC TECHNOLOGIES CO., LTD.
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QW-R103-019,A
UTC BA9741A
LINEAR INTEGRATED CIRCUIT
1.0
0.5
0
-0.5
-1.0
2.2
V CC =6V
RT1=10KΩ
2.0
Upper Voltage
1.8
1.6
Lower Voltage
1.4
-1.5
-20
0
20 40 60 80
Ambient Temperature : Ta (℃)
1.0
100K
Oscillator Frequency :fosc (Hz)
1M
Figure 5. Error Amplifier AC Gain Characteristic (40dB close)
50
Av
180
40
30
Gain :Av (dB)
0.8
0.6
0.4
20
10
0
90
θ
0
-10
-90
-20
-30
0.2
0
0
1.2
10K
100
Phase :θ(deg)
-2.0
-40
Figure4. Output Current vs.Output Saturation Voltage
1.2
Output Saturation Voltage: Vosat (V)
Figure 3. Swing Voltage vs. Frequency
Figure 2. Reference Voltage vs.Ambient Temperature
2.0
VCC =6V
1.5
Iref = -1mA
Swing Voltage :Vosc(V)
Reference Voltage Variation:△Vref (%)
ELECTRICAL CHARACTERISTIC CURVES
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.
UTC
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QW-R103-019,A