Datasheet

MAX8795A
TFT-LCD DC-DC Converter with
Operational Amplifiers
_______________________________________________________________________________________ 9
ELECTRICAL CHARACTERISTICS
(V
IN
= 3V, V
MAIN
= V
SUP
= 14V, V
PGND
= V
AGND
= V
BGND
= 0V, I
REF
= 25µA, T
A
= -40°C to +105°C, unless otherwise noted.) (Note3)
PARAMETER SYMBOL CONDITIONS MIN MAX UNITS
IN Supply Range V
IN
(Note 2) 2.5 6.0 V
IN Undervoltage-Lockout
Threshold
V
UVLO
V
IN
rising, typical hysteresis = 150mV 2.05 2.45 V
V
FB
= V
FBP
= 1.3V, V
FBN
= 0V,
LX not switching
1.0
IN Quiescent Current I
IN
V
FB
= 1.2V, V
FBP
= 1.4V, V
FBN
= 0V,
LX switching
3
mA
REF Output Voltage No external load 1.218 1.277 V
REF Undervoltage-Lockout
Threshold
Rising edge, typical hysteresis = 160mV 1.15 V
MAIN STEP-UP REGULATOR
Output Voltage Range V
MAIN
V
IN
18 V
Operating Frequency f
OSC
900 1400 kHz
FB Regulation Voltage V
FB
No load 1.198 1.260 V
FB Line Regulation V
IN
= 2.5V to 6V ±0.4 %/ V
FB Transconductance ∆I
COMP
= ±2.5µA 75 280 µS
LX On-Resistance R
LX
(
ON
)
I
LX
= 200mA 300 mΩ
LX Current Limit
I
LIM
V
FB
= 1.2V, duty cycle = 75% 2.5 3.5 A
OPERATIONAL AMPLIFIERS
SUP Supply Range V
SUP
618V
SUP Overvoltage Fault Threshold 18.0 19.9 V
SUP Supply Current I
SUP
Buffer configuration, V
POS_
= V
SUP
/ 2,
no load
5mA
Input Offset Voltage V
OS
(V
NEG_
, V
POS_
, V
OUT_
) ≅ V
SUP
/ 2 12 mV
Input Common-Mode Voltage
Range
V
CM
0V
SUP
V
Output Voltage Swing, High V
OH
I
OUT_
= 5mA
V
SUP
-
100
mV
Output Voltage Swing, Low V
OL
I
OUT_
= -5mA 100 mV
Source 75
Short-Circuit Current To V
SUP
/ 2
Sink 75
mA