AT1368
1-Channel Synchronous Buck PWM Controller
with Power Good Reset
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 N-
Channel 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 step-
down 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.
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
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
AT1368
1-Channel Synchronous Buck PWM Controller
with Power Good Reset
Pin Configuration
Ordering Information
Part number
AT1368A
AT1368B
AT1368B
Package
SSOP16
SSOP16
TSSOP16
Marking
AT1368AR
AT1368BR
AT1368BP
A: fosc =300KHz B: fosc =600KHz
Pin Description
Symbol
Pin No.
Descript
Symbol
Pin
No.(A/B)
Descript
FB
COMP
PVCC
PDRV
NDRV
PGND
GND
VCC
1
2
3
4
5
6
7
8
Inverting input to error
amplifier
Error amplifier output
Power blocks power
supply
Output for Pch-MOSFET
Output for Nch-MOSFET
Power blocks ground
Control blocks ground
Control blocks power
supply
SCP
CTL
NC
IN1
RESET
IN2
SS
3V3
9
10
11
12
13
14
15
16
Short-Circuit protection
Chip enable, high active
-
VCC monitor voltage
adjustable input pin
Power Good indicator
3V3 output monitor
adjustable input pin
Sotf-start
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
AT1368
1-Channel Synchronous Buck PWM Controller
with Power Good Reset
Absolute Maximum Ratings
Parameter
Power Supply Voltage
Source Average Current of PDRV,
NDRV
Sink Average Current of PDRV,
NDRV
Source Peak Current of PDRV,
NDRV
Sink Peak Current of PDRV,
NDRV
Input Voltage to Error Amplifier
Continuous power dissipation
Operating temperature
Storage temperature
Condition
—
—
—
—
—
—
SSOP16（Ta=+25℃）
—
—
Rated Value
Min.
Max.
-
+8
-
-50
-
-
-
-
-
-30
-55
50
-200
200
6.5
560
+85
+125
Unit
V
mA
mA
mA
mA
V
mW
0
C
0
C
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.
Recommended Operating Conditions
(Ta=+25
0
C)
Parameter
Power supply voltage
Control input voltage
Operating temperature
Symbol
V
CC
V
CTL
T
OP
Min.
2.5
0
-20
Values
Typ.
--
--
+25
Max.
7
7
+85
Unit
Ｖ
V
°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
AT1368
1-Channel Synchronous Buck PWM Controller
with Power Good Reset
Electrical Characteristics
(VCC = 5V,Ta =+25℃ , unless otherwise noted. )
Parameter
Input Supply Range
Quiescent Current
Current in standby mode
Entire device
Reference Voltage
Reference Voltage
line-regulation
Rference Variation
with Temperature
Input Offset Voltage
Source Current
Sink Current
Source current Variation
with temperature
Sink current Variation
with temperature
Unity Gain Bandwidth
Common Mode Input
Voltage Range
DC Open Loop Gain
Frequency
Sawtooth wave
oscillator (OSC)
High Level Voltage
Low Level Voltage
Variation with Power
Supply
Variation with
temperature
Charge Current of
SS
Invalid threshold
voltage of SS
Charge Current of
SS
Threshold Voltage of
SCP
Symbol
V
CC
I
CC
I
ST
V
REF
V
REF-Line
Condition
2.5
Duty=50%,
fOSC=600KHz
PDRV/NDRV No Load
CTL=0V
Ta =-20℃ to +85℃
VCC=2.5V to 7.0V
Ta =-20℃ to +85℃
Values
Min. Typ. Max.
--
1.0
7.0
1.5
10
1.20 1.22 1.24
1
0.5
1.0 1.5
-160 -120
5
1.5
10
2.0
-80
20
20
10.0
0.2
1.5
110
300
600
1.0
0.5
Unit
V
mA
µA
V
mV
%
mV
mA
μA
%
%
MHz
V
dB
350 KHz
700 KHz
V
V
2
7
%
%
µA
V
µA
V
V
IO
I
OH
I
OL
V
COMP
= V
REF
-0.5V
V
COMP
= 0.5V
Ta =-20℃ to +85℃
Ta =-20℃ to +85℃
Error amplifier
f
T
V
COM
A
V
fosc
fosc
AT1368A
AT1368B
250
500
Vcc=2.5V to 7V
Ta =-20℃ to +85℃
I
CSS
-1.0
1.0
I
CSS
-1.25
1.0
Soft-Start
Short-Circuit
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
AT1368
1-Channel Synchronous Buck PWM Controller
with Power Good Reset
PDRV Output
Block
Output source current
Output sink current
Output ON resistor
Output source current
NDRV Output
Block
Output sink current
Output ON resistor
I
source
I
sink
R
OH
R
OL
I
source
I
sink
R
OH
R
OL
V
IH
V
IL
I
CTL
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
Standby mode
CTL=5.0V
1.5
0
-
65
-
65
-130
100
18
16
-130
100
18
16
30
25
VCC
0.8
20
4.10 4.20 4.30
100
2.94
3.0
3.06
100
0.4
2.0
30
25
-80
-80
mA
mA
Ω
Ω
mA
mA
Ω
Ω
V
V
µA
V
mV
V
mV
V
µA
Control Block
CTL input voltage
CTL input Current
VCC reset ON voltage
VCC reset hysteresis
V
RSTON1
VCC rising
V
RSTON1 hys
VCC falling
V
RSTON2
3V3 rising
V
RSTON2 hys
3V3 falling
V
OL
I
Leak
I
L
=1mA
RESET Monitor
Block
3V3 reset ON voltage
3V3 reset hysteresis
Reset output voltage
Reset leakage current
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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