Electrical characteristics (continued) – Rainbow Electronics MAX8728 User Manual
Page 4
MAX8728
Low-Cost, Multiple-Output
Power Supply for LCD Monitors/TVs
4
_______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, V
IN
= V
INL
= V
SUPP
= 12V, V
OUT1
= +3.3V, V
SRC
= 28V, GND1 = GND2 = GNDP = GND = 0, I
REF
= 0, T
A
= 0°C
to +85°C. Typical values are at T
A
= +25°C, unless otherwise noted.)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Current-Sense Transresistance
0.6
1.2
1.8
V/A
LX2 On-Resistance
0.5
1.0
Ω
Soft-Start Period
3
ms
POSITIVE CHARGE-PUMP REGULATOR
FBP Regulation Voltage
1.98
2.00
2.02
V
FBP Line Regulation Error
V
IN
= V
SUPP
= 10.8V to 13.2V
6
mV
FBP Input Bias Current
V
FBP
= 2.1V
-50
+50
nA
DRVP p-Channel MOSFET
On-Resistance
4
Ω
DRVP n-Channel MOSFET
On-Resistance
1
Ω
FBP Fault Trip Level
Falling edge
1.536
1.600
1.664
V
Positive Charge-Pump Soft-Start
Period
3
ms
NEGATIVE CHARGE-PUMP REGULATOR
FBN Regulation Voltage
V
REF
- V
FBN
1.727
1.750
1.773
V
FBN Input Bias Current
V
FBN
= 250mV
-50
+50
nA
FBN Line Regulation
V
IN
= 10.8V to 13.2V
6
mV
DRVN p-Channel MOSFET
On-Resistance
4
Ω
DRVN n-Channel MOSFET
On-Resistance
1
Ω
FBN Fault Trip Level
Rising edge
600
mV
Negative Charge-Pump
Soft-Start Period
3
ms
SEQUENCE CONTROL
SHDN Input Low Voltage
0.4
V
SHDN Input High Voltage
2
V
SHDN Input Current
1
µA
EN Charge Current
During startup, V
EN
= 1.0V
4
5
6
µA
EN Turn-On Threshold
0.95
1.00
1.05
V
DEL Capacitor Charge Current
During startup, V
DEL
= 1.0V
4
5
6
µA
DEL Turn-On Threshold
0.95
1.00
1.05
V
GATE Output Sink Current
EN = high, GATE = IN
8
11
14
µA
GATE On Voltage
EN = high
V
IN
- 6
V
IN
- 5
V
IN
- 4
V
GATE Done Threshold
EN = high, V
GATE
_
DONE
- V
GATE
_
ON
0
1
V
GATE Pullup Resistance
EN = low, V
GATE
= V
IN
- 5V
1
k
Ω