MAX1578-MAX1579 Datasheet, PDF (2/13 Pages) Maxim Integrated Products – Complete Bias and White LED Power Supplies for Small TFT Displays

Complete Bias and White LED Power Supplies
for Small TFT Displays
ABSOLUTE MAXIMUM RATINGS
IN, CS, C1N, C2N, MAIN, ONBIAS, V_DD to GND.....-0.3V to +6V
CTRL to GND..................-0.3V to the lesser of +6V or (V_IN + 2V)
LX, OUT to GND .....................................................-0.3V to +37V
COMP to GND .............................................-0.3V to (V_IN + 0.3V)
CU1 to MAIN ............................................................-0.3V to +6V
CU2 to CU1 ..............................................................-0.3V to +6V
CU3 to CU2 ..............................................................-0.3V to +6V
NEG, CD2 to GND..................................................+0.3V to -12V
C1P, C2P to GND ...........................................-0.3V to (V_IN + 6V)
PMP, PMPB to GND ................................-0.3V to (V_MAIN + 0.3V)
GND to PGND .......................................................-0.3V to +0.3V
I_LX ...................................................................................1.0A_RMS
Continuous Power Dissipation (T_A = +70°C)
24-Pin 4mm x 4mm Thin QFN
CU3 to POS ............................................................-0.3V to +18V
(derate 20.8mW/°C above +70°C) .............................1667mW
CU3 to GND ...........................................................-0.3V to +18V
Short-Circuit Duration (MAIN, POS, NEG)..................Continuous
POS to GND ...........................................................-0.3V to +18V
Operating Temperature Range ...........................-40°C to +85°C
CD1 to MAIN ..........................................................+0.3V to -12V
Junction Temperature ......................................................+150°C
CD1 to GND .............................................................+0.3V to -6V
Storage Temperature Range .............................-65°C to +150°C
CD2 to CD1 ..............................................................+0.3V to -6V
Lead Temperature (soldering, 10s) ................................ +300°C
NEG to CD2..............................................................+0.3V to -6V
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(Circuit of Figure 3, V_IN = 3V, CTRL = ONBIAS = IN, T_A= -40°C to +85°C, typical values are at T_A= +25°C, unless otherwise noted. Note 1)
PARAMETER
CONDITIONS
MIN TYP MAX UNITS
IN Operating Supply Range
2.7
5.5
V
IN Undervoltage-Lockout (UVLO)
Threshold
Rising edge, 30mV hysteresis
2.1
2.35
2.6
V
IN Quiescent Current
Switching
IN Shutdown Current
V_CTRL = V_ONBIAS = 0V
T_A = +25°C
T_A = +85°C
Thermal Shutdown
Rising temperature, 20°C hysteresis (typ)
MAIN CHARGE PUMP WITH LINEAR REGULATOR
Main Pump Efficiency
I_LOAD = 25mA, V_IN = 3.9V
V_DD Charge-Pump Open-Loop
Output Impedance
V_IN ≥ 3.8V in 1.5x mode
V_IN ≥ 3.0V in 2.0x mode
Operating Frequency
V_DD Output Voltage
Charge-pump pause threshold
V_IN Falling Switchover to 2.0x Mode
V_IN Rising Switchover to 1.5x Mode
Quiescent Current
(Charge Pumps Only)
V_CTRL = 0V, ONBIAS = IN
3
5
mA
0.4
1
µA
1
+160
°C
83
%
9
20
Ω
7.5
20
200 250 300
kHz
5.2
5.5
5.7
V
3.75 3.85 3.95
V
3.8
3.9
4.0
V
0.87 1.30
mA
V_MAIN Regulation Voltage
0.1mA < I_LOAD < 25mA
4.9
5.0
5.1
V
Discharge Switch Resistance
at V_MAIN
V_ONBIAS = 0V
1
3
kΩ
POS, NEG CHARGE PUMPS
Operating Frequency
12.0 15.6 19.5
kHz
Duty Cycle
50
%
POS Pump Efficiency
POS Output Voltage
POS Discharge Switch Resistance
NEG Pump Efficiency
I_LOAD = 100µA
I_LOAD = 0 to 100µA
V_ONBIAS = 0V
I_LOAD = -100µA
97
%
13.9 14.7 15.3
V
3
6
kΩ
97
%
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