Electrical characteristics (continued) – Rainbow Electronics MAX8728 User Manual
Page 7
MAX8728
Low-Cost, Multiple-Output
Power Supply for LCD Monitors/TVs
_______________________________________________________________________________________
7
Note 1: When the inductor is in continuous conduction (EN = V
CC
or heavy load), the output voltage has a DC regulation level lower
than the error comparator threshold by 50% of the output voltage ripple. In discontinuous conduction (EN = GND with light
load), the output voltage has a DC regulation level higher than the error comparator threshold by up to 50% of the output
voltage ripple.
Note 2: Specifications to -40°C are guaranteed by design, not production tested.
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
=
-40°C to +85°C.) (Note 2)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
CHARGE-PUMP REGULATORS
FBP Regulation Voltage
1.97
2.02
V
FBN Regulation Voltage
V
REF
- V
FBN
1.71
1.78
V
SEQUENCE CONTROL
SHDN Input Low Voltage
0.4
V
SHDN Input High Voltage
2
V
EN Turn-On Threshold
0.95
1.10
V
DEL Turn-On Threshold
0.95
1.10
V
GATE On Voltage
EN = high
V
IN
- 6
V
IN
- 4
V
GATE Done Threshold
EN = high, V
GATE
_
DONE
- V
GATE
_
ON
0
V
POSITIVE GATE-DRIVER TIMING AND CONTROL SWITCHES
CTL Input Low Voltage
0.6
V
CTL Input High Voltage
2.1
V
SRC Input Voltage Range
38
V
V
MODE
= V
REF
, V
DEL
= V
CTL
= 3V
2.3
SRC Input Current
V
MODE
= V
REF
, V
DEL
= 3V, V
CTL
= 0
0.2
mA
SRC Switch On-Resistance
V
MODE
= V
REF
, V
DEL
= V
CTL
= 3V
30
Ω
DRN Switch On-Resistance
V
MODE
= V
REF
, V
DEL
= 3V, V
CTL
= 0,
V
GON
= 28V, V
THR
= 1.4V
50
Ω
MODE Current-Source Stop-
Voltage Threshold
MODE rising
1.2
1.6
V
MODE Voltage Threshold
Enabling DRN switch control in mode 2
0.8
1.2
V
THR-to-GON Voltage Gain
9.4
10.6
V/V