Datasheet

Step-Up, Step-Down Regulator, Gate-On Charge Pump,
and Boost-Buck Regulator for TV TFT LCD Display
MAX17122
_______________________________________________________________________________________ 7
ELECTRICAL CHARACTERISTICS (continued)
(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
LX3 Positive Current Limit Duty cycle = 60% 1.8 2.4 A
Maximum Duty Factor 85 94 %
NTC, SET Current
-40NC < T
A
< +25NC
97 104
FA
NTC, SET Effective Voltage
Range
0NC < T
A
< +25NC
0.1 1.65
V
+25NC < T
A
< +85NC
0.3 1.65
STEP-UP REGULATOR
Output-Voltage Range V
IN
20 V
Oscillator Maximum Duty Cycle 70 83 %
FB1 Regulation Voltage FB1 = COMP, C
COMP
= 1nF
-40NC < T
A
< +85NC
1.23 1.27 V
FB1 Output Undervoltage
Fault-Trip Level
Falling edge 0.96 1.04 V
FB1 Output Short-Trip Level Falling edge 0.35 0.4 V
FB1 Line Regulation 10.8V < V
IN
< 13.2V 0.15 %/V
FB1 Input-Bias Current V
FB1
= 2V 10 200 nA
FB1 Transconductance
DI = Q2.5FA at COMP, FB1 = COMP
150 560
FS
LX1 Bias Current V
FB1
= 1.5V, V
LX1
= 20V 40
FA
LX1 Current Limit V
FB1
= 1.1V, duty cycle = 25% 3.9 5.1 A
Current-Sense Transresistance 0.16 0.3 V/A
LX1 On-Resistance 200
mI
SS Charge Current 6 12
FA
POSITIVE CHARGE-PUMP LINEAR REGULATOR (DRVP)
FBP Regulation Voltage I
DRVP
= 1.35mA
-40NC < T
A
< +85NC
1.23 1.27 V
FBP Input-Bias Current V
FBP
= 1.25V -50 +50 nA
FBP Effective Load-Regulation
Error (Transconductance)
V
DRVP
= 15V, I
DRVP
= 0.6mA to 6mA 30 mV
DRVP Sink Current V
DRVP
= 15V, V
FBP
= 1.1V 10 30 mA
DRVP Off-Leakage Current V
DRVP
= 15V, V
FBP
= 1.5V 10
FA
FBP Fault-Trip Level Falling edge 0.96 1.04 V
NEGATIVE LINEAR-REGULATOR CONTROLLER (DRVN)
FBN Regulation Voltage I
DRVN
= 1.35mA
-40NC < T
A
< +85NC
0.98 1.02 V
FBN Input-Bias Current -50 +50 nA
FBN Pulldown Resistance EN1 = AGND 250 1000
I
FBN Fault-Trip Level Falling edge 0.45 0.55 V
FBN Effective Load-Regulation
Error (Transconductance)
V
DRVN
= -7.5V, I
DRVN
= 0.6mA to 6mA 46 mV
DRVN Source Current V
DRVN
= -7.5V, V
FBN
= 0.85V 10 mA
DRVN Off-Leakage Current V
DRVN
= -7.5V, V
FBN
= 1.15V 40
FA