PRODUCT DATASHEET
AAT2688
TM
SystemPower
4.5A PMIC Solution for 12V Adapter Systems with 2-Output High Performance Step-Down Converters
Electrical Characteristics1
VIN1 = 12.0V, VIN2 =3.3V; TA = -40°C to 85°C, unless otherwise noted. Typical values are at TA = 25°C.
Symbol
Description
Conditions
Min
Typ
Max
Units
Channel 1: 4.5A Step-Down (Buck) Converter
VIN1
Input Voltage
6.0
24.0
5.0
V
V
VIN1 Rising
VUVLO1
UVLO Threshold
VIN1 Hysteresis
VIN1 Falling
300
mV
V
V
V
%
3.0
0.8
VOUT1
VFB1
VOUT
Output Voltage Range
Feedback Pin Voltage
Output Voltage Accuracy
5.5
0.576 0.585 0.594
IOUT1 = 0 to 4.5A
-3.0
+3.0
(ΔVOUT/VOUT)/
ΔVIN
(ΔVOUT/VOUT)/
ΔIOUT
Line Regulation
Load Regulation
VIN1 = 6V to 24V, VOUT1 = 3.3V, IOUT1 = 4.5A
0.05
%/V
%/A
VIN1 = 12V, VOUT1 = 3.3V, IOUT1 = 0A to 4.5A
0.2
IQ1
ISHDN1
VOCP1
ILX1
Quiescent Current
Shutdown Current
Over-Current Offset Voltage
LX1 Pin Leakage Current
Maximum Duty Cycle
VEN1 = Low, No load, VFB1 = 1.2V
VEN1 = High, VL1 = 0V
VEN1 = Low, VIN1 = 6.0V to 24.0V, TA = 25°C
VIN1 = 24.0V, VEN1 = 5.0V
600
μA
μA
mV
μA
%
35
120
1.0
80
-1.0
100
DMAX
85
5.0
1.7
35
490
100
2.5
Pull-Up, VL1 = 4.5V
Pull-Down, VL1 = 4.5V
VL1 = 4.5V
RDL1
Low Side Drive Source Resistance
Ω
RDSON(H)
FOSC1
FFOLDBACK1
tS1
Hi Side On-Resistance
Oscillator Frequency
Short Circuit Foldback Frequency
Start-Up Time
mΩ
kHz
kHz
ms
350
2.7
650
Current Limit Triggered
From Enable Channel 1 to Output Regulation
Channel 2: 600mA Low Dropout (LDO) Regulator
VIN2
VDO2
IQ2
Input Voltage
Dropout Voltage
Quiescent (Ground) Current
Shutdown Current
5.5
1300
125
1.0
V
98% · VOUT2(NOM), IOUT2 = 600mA
No load
VEN2 = GND
1000
70
mV
μA
μA
ISHDN2
IOUT2= 1mA to 600mA, VIN2 = 2.7 to 5.5V,
TA = 25°C
IOUT2= 1mA to 600mA, VIN2 = 2.7 to 5.5V,
TA = -40°C to 85°C
-2.0
-3.5
+2.0
+3.5
%
VOUT2(TOL)
Output Voltage Tolerance
%
eN
Output Noise
BW = 300Hz to 50kHz
1kHz
250
67
μVRMS
PSRR
Power Supply Rejection Ratio
IOUT2 = 10mA
10kHz
1MHz
47
45
dB
ILIMIT2
tS2
Current Limit
Enable Start-Up Delay
700
800
15
mA
μs
From Enable Channel 2 to Output Regulation
Over-Temperature, EN Logic
Over-Temperature Shutdown
Threshold
135
15
°C
TSD1,2
Over-Temperature Shutdown
Hysteresis
Enable Threshold Low
Enable Threshold High
Input Low Current
°C
V
VEN1,EN2(L)
VEN1(H)
VEN2(H)
0.6
1.0
2.5
1.4
-1.0
V
IEN1,EN2
μA
1. The AAT2688 is guaranteed to meet performance specifications over the –40°C to +85°C operating temperature range and is assured by design, characterization and correla-
tion with statistical process controls.
w w w . a n a l o g i c t e c h . c o m
4
2688.2008.06.1.0
ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
