Datasheet

Step-Up, Step-Down Regulator, Gate-On Charge Pump,
and Boost-Buck Regulator for TV TFT LCD Display
MAX17122
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, V
IN
= V
IN2
= V
IN3
= 12V, T
A
= 0°C to +85°C. Typical values are at T
A
= +25NC, unless otherwise noted.)
PARAMETER CONDITIONS MIN TYP MAX UNITS
Output Voltage Adjust Range Step-down output 1.5 3.6 V
FB2 Fault-Trip Level Falling edge 0.96 1.0 1.04 V
FB2 Input-Bias Current V
FB2
= 1.5V 50 125 200 nA
DC Load Regulation 0.4A < I
LOAD
< 2A 0.5 %
DC Line Regulation No load, 10.8V < V
IN2
< 13.2V 0.1 %/V
LX2-to-IN2 nMOS Switch
On-Resistance
200 400
mI
LX2-to-GND1 nMOS Switch
On-Resistance
6 10 24
I
BST2-to-VL pMOS Switch
On-Resistance
6 12 24
I
Low-Frequency Operation
OUTB Threshold
LX2 only 0.8 V
Low-Frequency Operation
Switching Frequency
188 kHz
LX2 Positive Current Limit 2.5 3.0 3.5 A
Soft-Start Ramp Time Zero to full limit 3 ms
Maximum Duty Factor 68 75 82 %
BOOST-BUCK REGULATOR
FB3 Regulation Voltage No load, V
NTC
= 2V
T
A
= +25NC
1.63 1.65 1.67
V
0NC < T
A
< +85NC
1.62 1.65 1.68
FB3 Input-Bias Current V
FB3
= 0.5V -50 -125 -210 nA
FB3 Pulldown Resistance EN1 = AGND 300 1200
I
FB3 Fault-Trip Level Rising edge 1.9 2.0 2.1 V
DC Load Regulation 0A < I
LOAD
< 400mA 0.3 %
DC Line Regulation No load, 10.8V < V
IN2
< 13.2V 0.1 %/V
LX3-to-IN3 pMOS Switch
On-Resistance
200 400
mI
LX3 Positive Current Limit Duty cycle = 60% 1.8 2.1 2.4 A
Soft-Start Ramp Time Zero to full limit 3 ms
Maximum Duty Factor 85 89 94 %
NTC, SET Current
0NC < T
A
< +25NC
98 100 102
FA
+25NC < T
A
< +85NC
100
NTC, SET Effective Voltage
Range
0NC < T
A
< +25NC
0.1 1.65
V
+25NC < T
A
< +85NC
0.3 1.65