Rainbow Electronics MAX5953D User Manual
Page 5
MAX5953A/MAX5953B/MAX5953C/MAX5953D
IEEE 802.3af PD Interface and PWM Controllers
with Integrated Power MOSFETs
_______________________________________________________________________________________
5
ELECTRICAL CHARACTERISTICS (DC-DC Controller) (continued)
(All voltages referenced to GND, unless otherwise noted. V
HVIN
= +48V, C
INBIAS
= 1µF, C
REGOUT
= 2.2µF, R
RTCT
= 25k
Ω, C
RTCT
=
100pF, C
BST
= 0.22µF, V
CSS
= V
CS
= 0V, V
RAMP
= V
DCUVLO
= 3V, T
J
= 0°C to +125°C, unless otherwise noted. Typical values are at
T
J
= +25°C, unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
SOFT-START (CSS)
Soft-Start Current
I
CSS
V
CSS
= 0V
33
µA
INTEGRATING FAULT PROTECTION
FLTINT Source Current
I
FLTINT
80
µA
FLTINT Trip Point
V
FLTINT
rising
2.7
V
FLTINT Hysteresis
0.75
V
INTERNAL POWER FETs
On-Resistance
R
ON,POWER
V
DRVIN
= V
BST
= 9V,
V
XFRMRH
= V
SRC
= 0V, I
DS
= 50mA
0.4
0.8
Ω
Off-State Leakage Current
-5
+10
µA
Total Gate Charge Per Power
FET
15
nC
HIGH-SIDE DRIVER
Low to High Latency
t
LH-HS
Driver delay until FET V
GS
reaches 0.9 x
(V
BST
- V
XFRMRH
) and is fully on
80
ns
High to Low Latency
t
HL-HS
Driver delay until FET V
GS
reaches 0.1 x
(V
BST
- V
XFRMRH
) and is fully off
40
ns
Output Drive Voltage
V
BST
BST to XFRMRH with high side on
8
V
LOW-SIDE DRIVER
Low to High Latency
t
LH-LS
Driver delay until FET V
GS
reaches 0.9 x
V
DRVIN
and is fully on
80
ns
High to Low Latency
t
HL-LS
Driver delay until FET V
GS
reaches 0.1 x
V
DRVIN
and is fully off
40
ns
CURRENT-LIMIT COMPARATOR (CS)
Current-Limit Threshold
Voltage
V
ILIM
140
156
172
mV
Current-Limit Input Bias
Current
I
BILIM
0 < V
CS
< 0.3V
-2
+2
µA
Propagation Delay to XFRMRL
t
dILIM
From V
CS
rising (10mV overdrive) to
V
XFRMRL
rising
160
ns
BOOST VOLTAGE CIRCUIT (See Figure 9, QB)
Driver Output Delay
t
PPWMD
200
ns
One-Shot Pulse Width
t
PWQB
300
ns
QB R
DSON
Sinking 20mA
30
60
Ω
THERMAL SHUTDOWN
Shutdown Temperature
T
SH
Temperature rising
+160
°C
Thermal Hysteresis
T
H
20
°C