Digitally Adjustable LCD Bias Supply
MAX749
ABSOLUTE MAXIMUM RATINGS
V+ ................................................................................-0.3V, +7V
CTRL, ADJ, FB, DLOW, DHI, CS.....................-0.3V, (V+ + 0.3V)
Continuous Power Dissipation (T
A
= +70°C)
Plastic DIP (derate 9.09mW/°C above +70°C) ............727mW
SO (derate 5.88mW/°C above +70°C) .........................471mW
Operating Temperature Ranges:
MAX749C_A........................................................0°C to +70°C
MAX749E_A .....................................................-40°C to +85°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10sec) .............................+300°C
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
(2V < V+ < 6V, T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
V+ Voltage
2
6
V
FB Source Current
I
FBS
On power-up or reset, V
FB
= 0V (Note 1)
12.80
13.33
13.86
µA
Zero-Count FB Current
V
FB
= 0V
0.45
0.55
I
FBS
Full-Count FB Current
V
FB
= 0V
1.43
1.53
I
FBS
FB Offset Voltage
±15
mV
DAC Step Size (Note 2)
Monotonicity guaranteed, V
FB
= 0V
1.00
1.56
2.12
%I
FBS
DAC Linearity (Note 2)
V
FB
= 0V
±1
%I
FBS
Supply Rejection
V+ = 2V to 6V, full-count current
1.5
%I
FBS
Switching Frequency
100 to 500
kHz
Logic Input Current
0V < V
IN
< V+, CTRL, ADJ
±100
nA
Logic High Threshold (Note 3)
V
IH
CTRL, ADJ
1.6
V
Logic Low Threshold (Note 3)
V
IL
CTRL, ADJ
0.4
V
Quiescent Current
60
µA
Shutdown Current
15
µA
V+ to CS Voltage
Current-limit trip voltage
110
140
180
mV
DHI Source Current
V+ = 2V, V
DHI
= 1V
24
50
mA
DHI Drive Level
No load
V+ - 50mV
V+
V
DLOW On Resistance
V+ = 2V, V
DLOW
= 0.5V
5
10
Ω
Note 1:
The device is in regulation when V
FB
= 0V (see Figures 3 - 6).
Note 2:
These tests performed at V+ = 3.3V. Operation over supply range is guaranteed by supply rejection test of full-count current.
Note 3:
V
IH
is guaranteed by design to be 1.8V min for V+ = 2V to 6V for T
A
= T
MIN
to T
MAX
. V
IL
is guaranteed by design from
T
A
= T
MIN
to T
MAX
.
TIMING CHARACTERISTICS
PARAMETER
Minimum Reset Pulse Width
Minimum Reset Setup
Minimum Reset Hold
Minimum ADJ High Pulse Width
Minimum ADJ Low Pulse Width
Minimum ADJ Low to CTRL Low
SYMBOL
t
R
t
RS
t
RH
t
SH
t
SL
t
SD
CONDITIONS
V+ = 2V
V+ = 5V
Not tested
Not tested
V+ = 2V
V+ = 5V
V+ = 2V
V+ = 5V
V+ = 2V
V+ = 5V
MIN
T
A
= +25°C
TYP
MAX
125
25
0
0
15
10
170
60
70
20
85
85
400
150
200
85
300
85
0
0
100
100
500
200
250
100
T
A
= T
MIN
to T
MAX
MIN
MAX
400
100
UNITS
ns
ns
ns
ns
ns
ns
2
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MAXIM [ MAXIM INTEGRATED PRODUCTS ]
