Digitally Adjustable LCD Bias Supply
__________________________________________Typical Operating Characteristics
(T
A
= +25°C, L = 47µH, unless otherwise noted.)
EFFICIENCY vs. OUTPUT
CURRENT – PNP
MAX749TOC2-A
MAX749
EFFICIENCY vs. OUTPUT
CURRENT – PNP
MAX749TOC2-B
EFFICIENCY vs. OUTPUT
CURRENT – MOSFET
-24V
-12V
80
EFFICIENCY (%)
MAX749TOC2-C
85
80
78
76
EFFICIENCY (%)
74
72
70
68
66
-24V
V+ = 3V
R
BASE
= 160Ω
R
SENSE
= 0.25Ω
TRANSISTOR = ZTX750
-12V
-5V
85
80
EFFICIENCY (%)
-24V
-12V
-5V
-5V
75
V+ = 5V
R
SENSE
= 0.25Ω
TRANSISTOR: SMD10P05L
75
V+ = 3V
R
BASE
= 470Ω
R
SENSE
= 0.25Ω
TRANSISTOR: ZTX750
70
70
65
0
10
20
30
40
50
60
OUTPUT CURRENT (mA)
64
0
10 20 30 40 50 60 70 80 90 100
OUTPUT CURRENT (mA)
65
0
5 10 15 20 25 30 35 40 45 50
OUTPUT CURRENT (mA)
EFFICIENCY vs.
OUTPUT VOLTAGE
MAX749-TOC1-A
EFFICIENCY vs.
OUTPUT VOLTAGE
-20mA
-5mA
MAX749-TOC1-B
85
-20mA
80
EFFICIENCY (%)
-5mA
75
V+ = 3V
R
BASE
= 470Ω
R
SENSE
= 0.25Ω
TRANSISTOR : ZTX750
-40mA
85
80
EFFICIENCY (%)
-40mA
75
70
70
V+ = 5V
R
SENSE
= 0.25Ω
TRANSISTOR : SMD10P05L
65
-24 -22 -20 -18 -16 -14 -12 -10 -8 -6 -4
OUTPUT VOLTAGE (V)
65
-24 -22 -20 -18 -16 -14 -12 -10 -8 -6
OUTPUT VOLTAGE (V)
-4
LOAD CURRENT vs. INPUT VOLTAGE
MAX749-TOC3-A
LOAD CURRENT vs. INPUT VOLTAGE
450
400
LOAD CURRENT (mA)
350
300
250
200
150
100
50
0
-24V
-48V
2
3
4
INPUT VOLTAGE (V)
5
6
-12V
R
BASE
= 160Ω
-5V
R
SENSE
= 0.25Ω
TRANSISTOR = ZTX750
MAX749-TOC3-B
400
350
LOAD CURRENT (mA)
300
250
200
150
100
50
0
2
3
4
INPUT VOLTAGE (V)
5
6
-12V
-24V
-48V
R
BASE
= 470Ω
R
SENSE
= 0.25Ω
TRANSISTOR = ZTX750
-5V
500
_______________________________________________________________________________________
3
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
