Page 1
AT1368
1- Channel Synchronous Buck PWM Controller
with Power Good Reset
Features
• High efficiency (min. 90% On IO=300mA
~600mA)
• Using external P and N channel MOSFET
• Supports for down and up/down Zeta
conversion
• Maximum Duty 100%
• Oscillation frequency 300KHz or 600KHz
• Soft Start by an external capacity
• Output voltage accuracy ±2%
• Built-in ON/OFF Function
• Built-in Short-circuit Protection
• Stand-by current max. 10µA
• Quiescent Current 1mA
• Monitor the input voltage and 3V3 output
• Input voltage: 2.5V ~7.0V
Applications
• Slim-Type CD-ROM/DVD-ROM/CD-RW
• Power Supply for portable devices
• Main or Sub Power source foe notebook
computers and peripherals.
Block Diagram
General Description
The AT1368 provides complete control and
protection for a DC/DC converter optimized for
high-performance microprocessor applications. It
is designed to drive one P-Channel and one NChannel MOSFETs in a synchronous-rectified
buck topology. The AT1368 integrates all of the
control, output adjustment, monitoring and
protection functions into a single package. The
output voltage of the converter can be precisely
regulated with a maximum tolerance of ± 2% over
temperature and line voltage variations. The
AT1368 is a family of low-noise synchronous stepdown DC/DC converters that is ideally suited for
systems powered from a 1-cell Li-ion battery or
from a 3-cell to 4-cell NiCd, NiMH, or alkaline
battery. It can also be used to USB-Based power
system.
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
AT1368
1- Channel Synchronous Buck PWM Controller
with Power Good Reset
Pin Configuration
Ordering Information
Part number Package Marking
AT1368A SSOP16 AT1368AR
AT1368B SSOP16 AT1368BR
AT1368B TSSOP16 AT1368BP
A: fosc =300KHz B: fosc =600KHz
Pin Description
Symbol Pin No. Descript Symbol Pin
FB
COMP
PVCC
PDRV
NDRV
PGND
GND
VCC
1 Inverting input to error
amplifier
2 Error amplifier output
3 Power blocks power
supply
4 Output for Pch-MOSFET
5 Output for Nch-MOSFET
6 Power blocks ground
7 Control blocks ground
8 Control blocks power
supply
SCP
CTL
NC
IN1
RESET
IN2
SS
3V3
Descript
No.(A/B)
9 Short-Circuit protection
10 Chip enable, high active
11 -
12 VCC monitor voltage
adjustable input pin
13 Power Good indicator
14 3V3 output monitor
adjustable input pin
15 Sotf-start
16 Output voltage 3.3V
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
AT1368
1- Channel Synchronous Buck PWM Controller
with Power Good Reset
Absolute Maximum Ratings
Rated Value Parameter Condition
Unit
Min. Max.
Power Supply Voltage — - +8 V
Source Average Current of PDRV,
—- - 5 0 m A
NDRV
Sink Average Current of PDRV,
—- 5 0 m A
NDRV
Source Peak Current of PDRV,
— - -200 mA
NDRV
Sink Peak Current of PDRV,
—- 2 0 0 m A
NDRV
Input Voltage to Error Amplifier — - 6.5 V
Continuous power dissipation
SSOP16(T a=+25℃)
Operating temperature — -30 +85
Storage temperature — -55 +125
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.
-5 6 0m W
0
C
0
C
Recommended Operating Conditions
(Ta=+250C)
Va lu es Parameter Symbol
Min. Typ. Max.
Power supply voltage V
Control input voltage V
Operating temperature T
CC
CTL
OP
2.5 -- 7
0- -7V
-20 +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
AT1368
1- Channel Synchronous Buck PWM Controller
with Power Good Reset
Electrical Characteristics
(VCC = 5V,Ta =+25℃ , unless otherwise noted. )
Entire device
Error amplifier
Sawtooth wave
oscillator (OSC)
Soft-Start
Short-Circuit
Input Supply Range V
Quiescent Current I
Current in standby mode I
Reference Voltage V
Reference Voltage
line-regulation
V
REF-Line
Rference Variation
with Temperature
Input Offset Voltage V
Source Current I
Sink Current I
Source current Variation
with temperature
Sink current Variation
with temperature
Unity Gain Bandwidth f
Common Mode Input
Voltage Range
V
DC Open Loop Gain A
fosc
Frequency
fosc
High Level Voltage
Low Level Voltage
Variation with Power
Supply
Variation with
temperature
Charge Current of
SS
I
Invalid threshold
voltage of SS
Charge Current of
SS
I
Threshold Voltage of
SCP
Min. Typ. Max.
CC
2.5 -- 7.0 V
Duty=50%,
f
=600KHz
OSC
CC
PDRV/NDRV No Load
CTL=0V
ST
Ta =-20℃ to +85℃
REF
1.20 1.22 1.24 V
VCC=2.5V to 7.0V
Ta =-20℃ to +85℃
IO
V
= V
OH
OL
V
COMP
COMP
-0.5V 1.0 1.5 2.0 mA
REF
= 0.5V
-160 -120 -80
Ta =-20℃ to +85℃
Ta =-20℃ to +85℃
T
COM
V
0.2 1.5 V
AT1368A 250 300 350
AT1368B 500 600 700
Vcc=2.5V to 7V 2
Ta =-20℃ to +85℃
CSS
CSS
Va lu es Parameter Symbol Condition
Unit
1.0 1.5 mA
10
µ A
15m V
0.5 1.5 %
10 mV
μ A
20 %
20 %
10.0 MHz
110 dB
KHz
KHz
1.0
0.5
V
V
%
7%
-1.0
µ A
1.0 V
-1.25
µ A
1.0 V
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
AT1368
1- Channel Synchronous Buck PWM Controller
with Power Good Reset
PDRV Output
Block
NDRV Output
Block
Control Block
RESET Monitor
Block
Output source current I
Output sink current I
R
Output ON resistor
Output source current I
Output sink current I
R
Output ON resistor
CTL input voltage
CTL input Current I
VCC reset ON voltage V
VCC reset hysteresis V
3V3 reset ON voltage V
3V3 reset hysteresis V
RSTON1
RSTON1 hys
RSTON2
RSTON2 hys
Reset output voltage V
source
sink
OH
R
OL
source
sink
OH
R
OL
V
V
CTL
OL
Duty≥ 95% PDRV=0V
Duty≤ 5% PDRV=5V
PDRV=-15mA
PDRV=15mA
Duty≥ 95% NDRV=0V
Duty≤ 5% NDRV=5V
NDRV=-15mA
NDRV=15mA
Active mode
IH
Standby mode
IL
CTL=5.0V
VCC rising
VCC falling
3V3 rising
3V3 falling
IL =1mA
- -130 -80 mA
65 100 mA
18 30
16 25
- -130 -80 mA
65 100 mA
18 30
16 25
1.5 VCC V
00 . 8 V
4.10 4.20 4.30 V
2.94 3.0 3.06 V
Ω
Ω
Ω
Ω
20
µ A
100 mV
100 mV
0.4 V
Reset leakage current I
Leak
2.0
µ A
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
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AT1368
1- Channel Synchronous Buck PWM Controller
with Power Good Reset
Typical Application Circuit: 3V3 Output
L1: AT1368A: 22µ H/0.77A/104mΩ TDK-SLF6028T-220MR77
AT1368B: 10µ H/1A/74.5mΩ TDK-SLF6028T-100M1R0
R1: AT1368A: 100K
AT1368B: 10K
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
6
Page 7
AT1368
1- Channel Synchronous Buck PWM Controller
with Power Good Reset
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
AT1368
1- Channel Synchronous Buck PWM Controller
with Power Good Reset
Typical Application Circuit: 2V5 Output
*1V8 Output: R4:9.8KΩ R5:38.7KΩ
*Vin from 2.5V to 7V, disable SCP function
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
8
Page 9
AT1368
1- Channel Synchronous Buck PWM Controller
with Power Good Reset
Typical Application Circuit: Zeta converter 3V3 Output
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
9
Page 10
AT1368
1- Channel Synchronous Buck PWM Controller
with Power Good Reset
CH1:Reset CH2:SS CH3:Vout CH4:Vin
Fig.1 Vout:3.3V/1A Vin:5V Start-Up Waveform
Fig.2 Vout:2.5V/1A Vin:3.1V Start-Up Waveform
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
10
Page 11
AT1368
1- Channel Synchronous Buck PWM Controller
with Power Good Reset
Package Outline 16-pin SSOP
SYMBOL
A 1.35 1.60 1.75 0.053 0.063 0.069
A1 0.10 0.15 0.25 0.004 0.006 0.010
A2 - - 1.50 - - 0.059
b 0.20 - 0.30 0.008 - 0.012
C 0.18 - 0.25 0.007 - 0.010
D 4.80 4.85 5.00 0.189 0.191 0.197
ZD - 0.20 - - 0.008 -
E 5.79 5.99 6.20 0.228 0.236 0.244
E1 3.81 3.91 3.99 0.150 0.154 0.157
L 0.41 0.71 1.27 0.016 0.028 0.050
e - 0.64 - - 0.025 -
y - - 0.076 - - 0.003
θ 0° 8° 0° 8°
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
MILLIMETERS INCHES
MIN TYP MAX MIN TYP MAX
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AT1368
1- Channel Synchronous Buck PWM Controller
with Power Good Reset
Package Outline 16-pin TSSOP
SYMBOL
MILLIMETERS INCHES
MIN TYP MAX MIN TYP MAX
A 1.05 1.10 1.20 0.041 0.043 0.047
A1 0.05 0.10 0.15 0.002 0.004 0.006
A2 - 1.00 1.05 - 0.039 0.041
b 0.20 0.25 0.28 0.008 0.010 0.011
C - 0.127 - - 0.005 D 4.90 5.075 5.10 0.193 0.1998 0.200
E 6.20 6.40 6.60 0.244 0.252 0.260
E1 4.30 4.40 4.50 0.170 0.173 0.177
L 0.50 0.60 0.70 0.020 0.024 0.028
e - 0.65 - - 0.026 -
y - - 0.076 - - 0.003
θ 0° 8° 0° 8°
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
12
Page 13
AT1368
1- Channel Synchronous Buck PWM Controller
with Power Good Reset
Reflow Condition (IR/Convection or VPR Reflow)
Reference JEDEC Standard J-STD-020A
Classification Reflow Profiles
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.
120 seconds max.
10~150 seconds
10~20 seconds 60 seconds
219~225° C or
235~240° C
6° C /second max. 10° C/second max.
6 minutes max.
219~225° C or
235~240° C
Package Reflow Conditions
Pkg. Thickness ≥ 2.5mm
and all bags
Convection 219~225
VPR 219~225
°C
IR/Convection 219~225
°C
°C
Pkg. Thickness <2.5mm
and
Pkg. Volume ≥ 350 mm
Pkg. Thickness <2.5mm
and
3
Pkg. Volume <350 mm
Convection 235~240
VPR 235~240
IR/Convection 235~240
VPR
3
°C
°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
13