Rainbow Electronics MAX1885 - Manual (Page 6)

MAX1778/MAX1880–MAX1885
Quad-Output TFT LCD DC-DC
Converters with Buffer
6 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS
(V IN = +3.0V, SHDN = IN, V SUPP = V SUPN = V SUPB = V SUPL = 10V, LDOOUT = FBL, BUF- = BUFOUT, BUF+ = FLTSET = TGND =
PGND = GND, C REF = 0.22µF, C BUF = 1µF, T A = -40°C to +85°C, unless otherwise noted.) (Note 2)
PARAMETER SYMBOL CONDITIONS MIN MAX UNITS
Input Supply Range V IN 2.7 5.5 V
Input Undervoltage
Threshold
V UVLO V IN Rising, 40mV hysteresis (typ) 2.2 2.6 V
MAX1778/MAX1880/
MAX1883 (f
OSC = 1MHz)
1
IN Quiescent Supply
Current
I IN
V FB =
V FBP = 1.5V,
V
FBN = -0.2V
MAX1881/MAX1882/MAX1884/
MAX1885 (f
OSC = 500kHz)
1
mA
MAX1778/MAX1880
(f
OSC = 1MHz)
0.7
SUPP Quiescent Current I SUPP V FBP = 1.5V
MAX1881/MAX1882
(f
OSC = 500kHz)
0.5
mA
MAX1778/MAX1880
(f
OSC = 1MHz)
0.7
SUPN Quiescent Current I SUPN V FBN = -0.2V
MAX1881/MAX1882
(f
OSC = 500kHz)
0.5
mA
IN Shutdown Current V SHDN = 0, V IN = 5V 10 µA
SUPP Shutdown Current
V SHDN = 0, V SUPP = 13V,
MAX1778/MAX1880/MAX1881/MAX1882
10 µA
SUPN Shutdown Current
V SHDN = 0, V SUPN = 13V,
MAX1778/MAX1880/MAX1881/MAX1882
10 µA
SUPL Shutdown Current
V SHDN = 0, V SUPL = 13V,
MAX1778/MAX1881/MAX1883/MAX1884
10 µA
SUPB Shutdown Current V SHDN = 0, V SUPB = 13V 13 µA
MAIN STEP-UP CONVERTER
Main Output Voltage Range V MAIN V IN 13 V
Integrator enabled, C INTG = 1000pF 1.223 1.269
FB Regulation Voltage V FB
Integrator disabled (INTG = REF) 1.21 1.29
V
FB Input Bias Current I FB V FB = 1.25V, INTG = GND -50 +50 nA
MAX1778/MAX1880/MAX1883 0.75 1.25 MHz
Operating Frequency F OSC
MAX1881/MAX1882/MAX1884/MAX1885 375 625 kHz
Oscillator Maximum Duty
Cycle
79 91 %
LX Switch On-Resistance R LX(ON) I LX = 100mA 0.7 Ω
LX Leakage Current I LX V LX = 13V 20 µA
Phase I = soft-start (1024/f OSC ) 0.275 0.525
LX Current Limit I LIM
Phase IV = fully on (after 3072/f OSC ) 1.1 2.05
A
FB Fault Trip Level Falling edge, FLTSET = GND 1.07 1.14 V