MAX1518B Datasheet, PDF (7/25 Pages) Maxim Integrated Products – TFT-LCD DC-DC Converter with Operational Amplifiers

TFT-LCD DC-DC Converter with
Operational Amplifiers
Typical Operating Characteristics
(Circuit of Figure 1. V_IN = 5V, V_MAIN = 13V, V_GON = 24V, V_GOFF = -8V, V_OUT1 = V_OUT2 = V_OUT3 = V_OUT4 = V_OUT5 = 6.5V, T_A = +25°C
unless otherwise noted.)
STEP-UP EFFICIENCY
vs. LOAD CURRENT
100
90
V_IN = 5.0V
80 VIN = 3.3V
70
60
50
40
V_OUT = 13V
SWITCHING FREQUENCY
vs. INPUT VOLTAGE
1.4
1.3
1.2
1.1
STEP-UP SUPPLY CURRENT
vs. SUPPLY VOLTAGE
10
NO LOAD, SUP DISCONNECTED,
R1 = 95.3kΩ, R2 = 10.2kΩ
8
6
CURRENT INTO INDUCTOR
4
CURRENT INTO IN PIN
2
30
1
10
100
LOAD CURRENT (mA)
1.0
1000
2.5 3.0 3.5 4.0 4.5 5.0 5.5
INPUT VOLTAGE (V)
0
2.5 3.0 3.5 4.0 4.5 5.0 5.5
SUPPLY VOLTAGE (V)
STEP-UP REGULATOR SOFT-START
(HEAVY LOAD)
MAX1518B toc04
A
0V
STEP-UP REGULATOR PULSED
LOAD-TRANSIENT RESPONSE
MAX1518B toc05
A
200mA
B
0V
13V
B
C
0A
2ms/div
A: V_IN, 5V/div
B: V_MAIN, 5V/div
C: INDUCTOR CURRENT, 1A/div
TIMER DELAYED OVERLOAD PROTECTION
C
0A
10µs/div
A: LOAD CURRENT, 1A/div
B: V_MAIN, 200mV/div, AC-COUPLED
C: INDUCTOR CURRENT, 1A/div
REF VOLTAGE LOAD REGULATION
1.253
1.252
220ms
A
1.251
1.250
1.249
B
1.248
40ms/div
A: V_MAIN, 2V/div
B: INDUCTOR CURRENT, 1A/div
1.247
0
10
20
30
40
50
LOAD CURRENT (µA)
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