Datasheet

Step-Up, Step-Down Regulator, Gate-On Charge Pump,
and Boost-Buck Regulator for TV TFT LCD Display
MAX17122
4 ______________________________________________________________________________________
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
STEP-UP REGULATOR
Output-Voltage Range V
IN
20 V
Oscillator Maximum Duty Cycle 70 76 83 %
FB1 Regulation Voltage V
FB1
= COMP, C
COMP
= 1nF
T
A
= +25NC
1.2375 1.250 1.2625
V
0NC < T
A
< +85NC
1.23 1.27
FB1 Output Undervoltage
Fault Trip Level
Falling edge 0.96 1.0 1.04 V
FB1 Output Short Trip Level Falling edge 0.35 0.375 0.4 V
FB1 Load Regulation 0 < I
LOAD
< full, transient only -1 %
FB1 Line Regulation 10.8V < V
IN
< 13.2V 0.08 0.15 %/V
FB1 Input-Bias Current V
FB1
= 2V 10 125 200 nA
FB1 Transconductance
DI = Q2.5FA at COMP, FB1 = COMP
150 320 560
FS
FB1 Voltage Gain FB1 to COMP 3500 V/V
LX1 Bias Current V
FB1
= 1.5V, V
LX1
= 20V 10 40
FA
LX1 Current Limit V
FB1
= 1.1V, duty cycle = 25% 3.9 4.5 5.1 A
Current-Sense Transresistance 0.16 0.23 0.3 V/A
LX1 On-Resistance 100 200
mI
SS Full Output Level 1.25 V
SS Charge Current 6 9 12
FA
POSITIVE CHARGE-PUMP LINEAR REGULATOR (DRVP)
FBP Regulation Voltage I
DRVP
= 1.35mA
T
A
= +25NC
1.2375 1.250 1.2625
V
0NC < T
A
< +85NC
1.23 1.27
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 15 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 0.1 10
FA
FBP Fault-Trip Level Falling edge 0.96 1.0 1.04 V
Positive Regulator Soft-Start
Period
7-bit voltage ramp with filtering to prevent high peak
currents
3 ms
NEGATIVE LINEAR-REGULATOR CONTROLLER (DRVN)
FBN Regulation Voltage I
DRVN
= 1.35mA
T
A
= +25NC
0.985 1 1.015
V
0NC < T
A
< +85NC
0.98 1 1.02
FBN Input-Bias Current -50 +50 nA
FBN Pulldown Resistance EN1 = AGND 250 1000
I
FBN Fault-Trip Level Falling edge 0.45 0.5 0.55 V
FBN Effective Load-Regulation
Error (Transconductance)
V
DRVN
= -7.5V, I
DRVN
= 0.6mA to 6mA 23 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