Advanced Analog Technology, Inc.
Advanced Analog Technology, Inc
.
Page 1 of 16 V1.0
AAT1351
Details are subject to change without notice
2-CHANNEL SWITCHING REGULATOR
FEATURES
Complete PWM Power Control Circuitry
Under-Voltage Lockout (UVLO) Protection
Open Drain Output
Output Short Circuit Protection
Low Dissipation Current1.6mA
Dead-Time Control0% to 100%
Wide Operating Frequency
10 kHz to 800 kHz
DD
V
Range4.0V to 14.0V
PIN CONFIGURATION
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
C
t
R
t
IE1
OE1
DTC1
GND
OUT1
V
REF
NE2
SCP
IE2
OE2
DTC2
OUT2
TOP VIEW
NE1
V
DD
GENERAL DESCRIPTION
The AAT1351 provides an integrated two-channel
pulse-width-modulation (PWM) solution for the
power supply of DC-DC system; this device offers
the systems engineer flexibility to tailor-make the
power supply circuitry for specific applications.
Each channel contains its own error amplifier,
PWM comparator, deadtime control (DTC) and
output driver. The under-voltage protection,
oscillator, short circuit protection and voltage
reference circuit are the common features for the
two channels.
Both channels of AAT1351 can be used for DC-DC
converter operations including step-up, step-down,
and inverting. Dead-time control can be set to
provide 0% to 100% dead-time through a resistive
divider network. Soft-start can be implemented by
paralleling the DTC resistor with a capacitor. Two
dead-time control inputs are assigned for channel 1
(CH1) and channel 2 (CH2) individually, and dead-
time control inputs can be used to control on / off
operation.
With a minimum number of external components,
the AAT1351 offers a simple and cost effective
solution.
SOP-16 PACKAGE
Advanced Analog Technology, Inc.
Advanced Analog Technology, Inc
.
Page 2 of 16 V1.0
AAT1351
PIN DESCRIPTION
PIN NO NAME I/O
DESCRIPTION
1
t
C
I External Timing Capacitance
2
t
R
I External Timing Resistance
3 NE1
I
Noninverting Input of Error Amplifier 1
4
IE1
I Inverting Input of Error Amplifier 1
5
OE1
I Output of Error Amplifier 1
6
DTC1
I Output 1 Dead-Time / Soft-Start Setting
7 OUT1
O
Output
1
8 GND
Ground
9
DD
V
I Power Supply
10 OUT2
O
Output
2
11
DTC2
I Output 2 Dead-Time / Soft-Start Setting
12
OE2
I Output of Error Amplifier 2
13
IE2
I Inverting Input of Error Amplifier 2
14 NE2 I
Noninverting Input of Error Amplifier 2
15
SCP
I Timer Latch Setting
16
REF
V
O Reference Voltage (2.5V) Output
Advanced Analog Technology, Inc.
Advanced Analog Technology, Inc
.
Page 3 of 16 V1.0
AAT1351
ABSOLUTE MAXIMUM RATINGS
CHARACTERISTICS SYMBOL
VALUE
UNIT
Supply Voltage
DD
V
14.0 V
Input Voltage (
-
IE
, DTC)
I
V
DD
V
V
Output Voltage
O
V
DD
V +0.3
V
Output Current
O
I
120 mA
Operating Free-Air Temperature Range
C
T
20
-
to +85
o
C
Storage Temperature Range
storage
T
45
-
to +125
o
C
Power Dissipation
d
P
500 mW
RECOMMENDED OPERATING CONDITIONS
SYMBOL
MIN
MAX
UNIT
Supply Voltage,
DD
V
DD
V
4.0 14.0 V
Input Voltage, IE1, IE2
cm
V
0.5 1.6 V
Output Voltage
O
V
0
DD
V
V
Oscillator (OSC) Capacitance
OSC
C
100 15,000 pF
Oscillator (OSC) Resistance
OSC
R
5.1 50.0
k
Oscillator (OSC) Frequency
OSC
f
10 800 kHz
Output Current,
1
OUT
I
,
2
OUT
I
O
I
- 100 mA
Operating Free-Air Temperature
C
T
20
-
85
o
C
Advanced Analog Technology, Inc.
Advanced Analog Technology, Inc
.
Page 4 of 16 V1.0
AAT1351
ELECTRICAL CHARACTERISTICS,
DD
V
= 6.0V (UNLESS OTHERWISE
SPECIFIED) (SEE NOTE 1)
OSCILLATOR
PARAMETER
TEST CONDITION
MIN
TYP MAX UNIT
Frequency
OSC
f
OSC
C
= 330pF,
OSC
R
= 10
k
160 200 240 kHz
Frequency Changes with
DD
V
V
f
DD
V = 4.0V to 14.0V,
C
T = 25
o
C
OSC
C
= 330pF,
OSC
R
= 10
k
- 1 - %
UNDER VOLTAGE PROTECTION
PARAMETER
TEST
CONDITION
MIN TYP
MAX
UNIT
Upper Threshold Voltage
UPH
V
C
T = 25
o
C
-
2.9 - V
Lower Threshold Voltage
UPL
V
C
T = 25
o
C
-
2.53 - V
Hysteresis (
UPH
V
UPL
V
)
HYS
V
C
T = 25
o
C
-
0.37 - V
SHORT CIRCUIT PROTECTION CONTROL
PARAMETER
TEST
CONDITION
MIN
TYP
MAX
UNIT
Input Threshold Voltage
1
r
V
CH1, CH2
-
1.18
-
V
Short Circuit Detect
Threshold Voltage
2
r
V
0.65
0.70
0.75
V
SCP Terminal Source
Current
SCP
I
20
-
15
-
10
-
A
Stand-by Voltage
V
STB
-
50
100
mV
Latch Voltage
V
LT
-
30
100
mV
Note 1: Typical values of all parameters are specified at
C
T
=25
o
C.
Advanced Analog Technology, Inc.
Advanced Analog Technology, Inc
.
Page 5 of 16 V1.0
AAT1351
ELECTRICAL CHARACTERISTICS,
DD
V
= 6.0V (UNLESS OTHERWISE
SPECIFIED) (SEE NOTE 1) (CONT.)
REFERENCE VOLTAGE
PARAMETER
TEST
CONDITION
MIN
TYP
MAX UNIT
Reference Voltage
REF
V
mA
1
I
REF
-
=
,
C
T = 25
o
C
2.4 2.5 2.6 V
Input Voltage Regulation
RI
V
mA
1
I
REF
-
=
,
V
DD
= 4.0V to 14.0V
- 1 5 mV
Output Regulation
RO
V
mA
1
.
0
I
REF
-
=
to
0
.
3
-
mA
- 1 10
mV
EA (ERROR AMPLIFIER)
PARAMETER
TEST CONDITION
MIN
TYP MAX UNIT
Input Offset Voltage
IO
V CH1, CH2, Unity Gain
- - 6
mV
Input Bias Current
IB
I
CH1, CH2
- 15
100
nA
Input Voltage Range
IR
V CH1, CH2
0.5 - 1.6 V
Open-Loop Voltage Gain
VO
A
70 85 - dB
+
OS
V
2.3 2.5 -
Output Voltage Swing
-
OS
V
- 0.7
0.9
V
Output Sink Current
+
OS
I
OE=1.25V
3 20 - mA
Output Source Current
-
OS
I
OE=1.25V
75
-
45
-
-
A
Common-Mode Rejection
Ratio
CMRR
60 80 - dB
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