Manual

MAX1747
Triple Charge-Pump TFT LCD
DC-DC Converter
_______________________________________________________________________________________ 5
PARAMETER SYMBOL CONDITIONS MIN MAX UNITS
REFERENCE
Reference Voltage V
REF
-2µA < I
REF
< 50µA 1.222 1.269 V
Reference Undervoltage
Threshold
V
REF
rising 0.95 1.18 V
LOGIC SIGNALS
SHDN
Input Low Voltage 0.4 V
SHDN
Bias Voltage I
SHDN
= 22µA 580 900 mV
SHDN
Input Current Range I
SHDN
For 200kHz to 2MHz operation 3 65 µA
RDY
Output Low Voltage I
SINK
= 2mA 0.5 V
RDY
Output High Leakage V
RDY
= 13V 1 µA
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= V
SUPM
= +3.0V, V
SUPP
= V
SUPM
= +5V, TGND = PGND = GND, I
SHDN
= 22µA, C
OUT
= 2
✕
4.7µF, C
REF
= 0.22µF, C
INTG
=
1500pF, V
OUT
= +5V, T
A
= -40°C to +85°C, unless otherwise noted.) (Note 1)
Note 1: Specifications from 0°C to -40°C are guaranteed by design, not production tested.
Typical Operating Characteristics
(Circuit of Figure 1, V
IN
= V
SUPM
= +3.3V, T
A
= +25°C, unless otherwise noted.)
4.97
4.99
4.98
5.01
5.00
5.02
5.03
0200100 300 400
MAX1747 toc01
I
OUT
(mA)
V
OUT
(V)
MAIN OUTPUT EFFICIENCY
vs. LOAD CURRENT
(MAIN CHARGE PUMP ONLY)
V
IN
= 3.3V
V
IN
= 4.0V
V
IN
= 2.8V
40
60
50
80
70
90
100
0200100 300 400
MAX1747 toc02
I
OUT
(mA)
EFFICIENCY (%)
MAIN OUTPUT EFFICIENCY
vs. LOAD CURRENT
(MAIN CHARGE PUMP ONLY)
V
OUT
= 5V
V
IN
= 3.3V
V
IN
= 4.0V
V
IN
= 2.8V
40
60
50
80
70
90
100
0200100 300 400
MAX1747 toc03
I
OUT
(mA)
EFFICIENCY (%)
MAIN OUTPUT EFFICIENCY
vs. LOAD CURRENT
(MAIN CHARGE PUMP ONLY)
V
OUT
= 5V
V
IN
= 3.3V
V
IN
= 4.0V
V
IN
= 2.8V
V
NEG
= -7V WITH I
NEG
= 10mA
V
POS
= 12V WITH I
POS
= 5mA