Datasheet

MAX1997/MAX1998
Quintuple/Triple-Output TFT LCD Power Supplies
with Fault Protection and VCOM Buffer
6 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= 3V, V
DDB
= 10V, SHDN = ONDC = FREQ = IN, C
REF
= 0.22µF, PGND = GND, T
A
= -40°C to +85°C, unless otherwise noted.)
(Note 3)
PARAMETER CONDITIONS
MIN
TYP
MAX
UNITS
NEGATIVE LINEAR-REGULATOR CONTROLLER (REG N)
FBN Regulation Voltage I
DRVN
= 100µA 95 155 mV
FBN Fault Trip Level V
FBN
rising
325
475 mV
FBN Effective Load Regulation Error
(Transconductance)
V
DRVN
= -10V, I
DRVN
= 0.05mA to 5mA 30 mV
DRVN Source Current V
FBN
= 200mV, V
DRVN
= -10V 1 mA
VCOM BUFFER (MAX1997 only)
V
DDB
Supply Range 4.5 13 V
V
DDB
Supply Current V
FBPB
= V
FBNB
= 5V, V
DDB
= 9V 900 µA
Input Offset Voltage V
FBPB
= 2.5V, no load -5 +5 mV
Input Bias Current V
FBPB
= V
FBNB
= 1.2V to V
DDB
- 1.2V 1 µA
Input Common-Mode Range V
DDB
= 4.5V to 13V 1.2
V
DDB
-
1.2
V
Out Current Drive ± 100mV overdrive, V
OUTB
= 3V or 7V
±150
mA
LOGIC SIGNALS (SHDN, ONDC)
Input Low Voltage 100mV typ hysteresis 0.4 V
Input High Voltage 1.6 V
CONTROL INPUTS AND OUTPUTS
FREQ, PFLT Input Low Voltage 1V
FREQ, PFLT Input High Voltage
V
IN
- 1
V
FREQ, PFLT Input Current FREQ, PFLT = GND or IN -50 +50 µA
Note 1: Quiescent current does not include switching losses.
Note 2: Guaranteed by design, not production tested.
Note 3: Specifications to -40°C are guaranteed by design, not production tested.
Note 4: The VCOM buffer load transient settling time is measured with the following circuit:
MAX1997
20kΩ
20kΩ
R
L
25Ω
C
L
10nF
FBPB
V
DDB
GND
1µF
1µF
OUTB
FBNB
V
GAMMA
8.6V
V
SOURCE
9V
V
x
V
DRIVE
8V