The AT1729 is a PWM DC/DC converter control
IC with 3 channel outputs that can directly drive
power MOSFET. This IC ia suitable for very small
DC/DC converters because of their small and thin
package(1.1 mm max.), and high operation
frequency (up to 1.0 MHz).
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879 Email: service@aimtron.com.tw
1
Page 2
AT1729
3-Channel PWM Controller for LCD Bias
Pin Configuration
Preliminary
Ordering Information
Part numberPackageMarking
AT1729TSSOP16-
Pin Description
SymbolPin
No.(A/B)
FB1
IN1
IN2
GND
PGND
FB2
IN3
FB3
1CH1 error amplifier output
2CH1 inverting input to
error amplifier
3
CH2 inverting input to
error amplifier
4Control blocks ground
5Power blocks ground
6CH2 error amplifier output
7
CH3 inverting input to
error amplifier
8CH3 error amplifier output
DescriptSymbolPin
No.(A/B)
OUT3
OUT2
VCC
OUT1
REG
CT
CS3
CS1_2
9CH3 output for Pch-
10CH2 output for Nch-
11Power Supply
12CH1 output for Nch-
13Regulated voltage output
14Oscillator timing
15Sotf-start for CH3
16Soft-star for CH1/2
Descript
MOSFET
MOSFET
MOSFET
capacitor
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879 Email: service@aimtron.com.tw
2
Page 3
AT1729
3-Channel PWM Controller for LCD Bias
Absolute Maximum Ratings
Preliminary
Rated ValueParameterCondition
Unit
Min.Max.
Power Supply Voltage—-+8V
Source Average Current of OUT1
—--50mA
OUT2, OUT3
Sink Average Current of OUT1
—-50mA
OUT2, OUT3
Input Voltage to Error Amplifier—-6.5V
Continuous power dissipation
TSSOP16(Ta=+25℃)
Operating temperature—-30+85
Junction temperature—-+125
Storage temperature—-40+150
Lead temperature—-+300
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are
stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the
operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended
periods may affect device reliability.
-500mW
0
C
0
C
0
C
0
C
Recommended Operating Conditions
(Ta=+250C)
Va lu esParameterSymbol
Min.Typ.Max.
Power supply voltageV
Oscillation frequencyf
Operating temperatureT
CC
OSC
OP
2.5--7
1005001000KHz
-30+25+85°C
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879 Email: service@aimtron.com.tw
3
Unit
V
Page 4
AT1729
3-Channel PWM Controller for LCD Bias
Electrical Characteristics
(VCC = 3V,Ta =+25℃, unless otherwise noted.)
Preliminary
Entire device
Error amplifier
Sawtooth wave
oscillator (OSC)
Regulated Voltage
for internal Control
Block
Input Supply Range
VCC Undervoltage
Lockout
Reference VoltageV
Reference Voltage
line-regulation
V
CC
UVLO1.95 2.05 2.15V
REF
V
REF-Line
Rference Variation
with Temperature
Operating CurrentI
CC
Input Offset VoltageV
Source Current
(CH1,2,3)
Sink Current(CH1,2,3)I
I
OH
OL
Source current Variation
with temperature
Sink current Variation
with temperature
Unity Gain Bandwidthf
Common Mode Input
Voltage Range
T
V
COM
DC Open Loop GainA
Frequencyfosc
High Level Voltage
Low Level Voltage
Variation with Power
Supply
Variation with
temperature
Regulated VoltageV
REG
Variation with Power
Supply
Variation with
Temperature
Source CurrentI
REG
Va lu esParameterSymbolCondition
Min. Typ. Max.
2.5--7.0V
0.98 1.00 1.02V
VCC=2.5V to 7.0V
15mV
Ta =-30℃ to +85℃
0.51.5%
Duty=50%,
3.03.8mA
-160 -120-80
IO
f
=500KHz
OSC
VFB = V
REG
-0.5V
VFB = 0.5V2.02.53.0mA
Ta =-30℃ to +85℃
Ta =-30℃ to +85℃
2.0 MHz
0.21.5V
V
C
=150pF480550620
T
=150pF1.0
C
T
=150pF0.5
C
T
80dB
Vcc=2.5V to 7V2
Ta =-30℃ to +85℃
CO =0.1μF
2.16 2.20 2.24V
Vcc=2.5V to 7V
Ta =-30℃ to +85℃
-40--15
Unit
10mV
μA
20%
20%
kHz
V
V
%
7%
1.5%
1.5%
mA
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879 Email: service@aimtron.com.tw
4
Page 5
AT1729
3-Channel PWM Controller for LCD Bias
Soft-Start and Duty
Section
Timer Latch Section
(TL)
Thermal Shuntdown
Section
Output Section
Charge Current of
CS1_2(Source)
Charge Current of
CS3(Sink)
Max. Duty of CH1,2
Max. Duty of CH3
Invalid TL threshold
voltage of CS1_2
Invalid TL threshold
voltage of CS3
Threshold Voltage of
FB1,2
Threshold Voltage of
FB3
Start up countCount
Start up timeT
Threshold TemperatureT
Rise time of OUT1,2t
Rise time of OUT3t
Fall time of OUT1,2t
Fall time of OUT3t
High Level on
Resistance of OUT1,2
Low Level on
Resistance of OUT1,2
High Level on
Resistance of OUT3
Low Level on
Resistance of OUT3
I
CS1_2
I
V
TLTH1 2
V
TLTH3
R
1_2AH
R
R
R3
CS3
f
=500KHz
OSC
f
=500KHz
OSC
TL
OH
CO =1000pF between
r1_2
OUT1,2-GND
CO =1000pF between
r3
VCC-OUT3
CO =1000pF between
f1_2
OUT1,2-GND
CO =1000pF between
f3
VCC-OUT3
I
=-150mA
OUT1_2
I
=150mA
3AH
AL
OUT1_2
I
OUT3
I
OUT1_2
=-150mA
=150mA
1_2AL
Preliminary
-1.0mA
1.0mA
808790%
808690%
0.3V
1.32.V
1.32V
0.3V
16
2
105119137ms
140
202535ns
202535ns
202535ns
202535ns
2.54.05.5
2.54.05.5
2.54.05.5
2.54.05.5
0
C
Ω
Ω
Ω
Ω
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879 Email: service@aimtron.com.tw
5
Page 6
AT1729
3-Channel PWM Controller for LCD Bias
Typical Application Circuit
Preliminary
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879 Email: service@aimtron.com.tw
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879 Email: service@aimtron.com.tw
7
Page 8
AT1729
C
3-Channel PWM Controller for LCD Bias
Reflow Condition (IR/Convection or VPR Reflow)
Reference JEDEC Standard J-STD-020A
Classification Reflow Profiles
Preliminary
Convection or
IR/Convction
Average Heating Rate(180°C to peak)5°C/second max.10°C/second max.
Preheat Temperature(125±20°C)
Temperature maintained above 180°C
Time within 5°C of actual Peak
Temperature
Peak Temperature Range(Note 1)
Cooling Rate
Time 25°C to Peak Temperature
*1 The maximum peak temperatures for IR and VP reflow are depending on package dimensions.