Datasheet

Step-Up, Step-Down Regulator, Gate-On Charge Pump,
and Boost-Buck Regulator for TV TFT LCD Display
MAX17122
6 ______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS
(Circuit of Figure 1, V
IN
= V
IN2
= V
IN3
= 12V, T
A
= -40°C to +85°C.) (Note 2)
PARAMETER CONDITIONS MIN TYP MAX UNITS
GENERAL
IN, IN2, IN3
Input-Voltage Range
8 16.5 V
IN + IN2 + IN3
Quiescent Current
Only LX2 and LX3 switching (V
FB1
= V
FBP
= 1.5V, V
FB2
=
1.1V, V
FB3
= 1.8V, V
FBN
= 1.5V); V
EN1
= V
EN2
= 5V
15 mA
IN + IN2 + IN3
Quiescent Current
LX2 and LX3 not switching (V
FB1
= V
FB2
= V
FBP
= 1.5V,
V
FBN
= 1.5V, V
FB3
= 0); V
EN1
= V
EN2
= 5V
4 mA
IN + IN2 + IN3
Shutdown Current
EN1 = EN2 = AGND (shutdown) 1 mA
SMPS Operating Frequency 638 862 kHz
IN Undervoltage-Lockout
Threshold
V
IN
rising, 2.5% hysteresis 6 8 V
VL REGULATOR
VL Output Voltage
I
VL
= 10mA, V
FB1
= V
FB2
= V
FBP
= 1.1V, V
FBN
= 0.75V,
V
FB3
= 1.8V (all regulators switching)
4.9 5.1 V
VL Undervoltage-Lockout
Threshold
VL rising, 2.5% hysteresis
3.6 4.4 V
STEP-DOWN REGULATOR
OUTB Voltage in Fixed Mode FB2 = AGND, no load (Note 1)
-40NC < T
A
< +85NC
3.25 3.35 V
FB2 Voltage in Adjustable Mode V
OUTB
= 3.3V, no load (Note 1)
-40NC < T
A
< +85NC
1.23 1.27 V
FB2 Adjustable-Mode
Threshold Voltage
Dual-mode comparator 0.10 0.20 V
Output Voltage Adjust Range Step-down output 1.5 3.6 V
FB2 Fault-Trip Level Falling edge 0.96 1.04 V
FB2 Input-Bias Current V
FB2
= 1.5V 50 200 nA
LX2-to-IN2 nMOS Switch
On-Resistance
400
mI
LX2-to-GND1 nMOS Switch
On-Resistance
6 24
I
BST2-to-VL pMOS Switch
On-Resistance
6 24
I
LX2 Positive Current Limit 2.5 3.5 A
Maximum Duty Factor 68 82 %
BUCK-BOOST REGULATOR
FB3 Regulation Voltage No load, V
NTC
= 2V
-40NC < T
A
< +85NC
1.62 1.68 V
FB3 Input-Bias Current V
FB3
= 0.5V -50 -210 nA
FB3 Pulldown Resistance EN1 = AGND 300 1200
I
FB3 Fault-Trip Level Rising edge 1.9 2.1 V
LX3-to-IN3 pMOS Switch
On-Resistance
400
mI