Datasheet
4Maxim Integrated
MAX5988A/MAX5988B
IEEE 802.3af-Compliant, High-Efficiency, Class 1/Class 2,
Powered Devices with Integrated DC-DC Converter
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= 48V, R
SIG
= 24.9kω, LED, V
CC
, SL, ULP, WK, RESET, LDO_OUT unconnected, WAD = LDO_EN = LDO_IN = PGND = GND,
C1 = 68nF, C2 = 10µF, C3 = 1µF (see Figure 3), V
FB
= V
AUX
= 0V, LX unconnected, CLASS2 = 0V, MPS = 0V. All voltages are refer-
enced to GND, unless otherwise noted. T
A
= T
J
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 3)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
CLASS2, MPS Voltage Falling
Threshold
V
CLASS2, FALL
0.4 V
RESET Output Voltage Low V
OL_RESET
I
SINK
= 1mA 0.2 V
RESET, CLASS2, MPS Leakage I
LOG_LEAK
-10 +10 µA
INTERNAL REGULATOR WITH BACK BIAS
V
AUX
Input Voltage Range V
AUX
Inferred from V
AUX
input current 4.75 14 V
V
AUX
Input Current I
AUX
V
AUX
from 4.75V to 14V 0.65 3.1 mA
V
DRV
Output Voltage 4.2 5.5 V
SLEEP MODE
WK and ULP Logic Threshold V
TH
V
WK
falling and V
ULP
rising and
falling
1.6 2.9 V
SL Logic Threshold Falling 0.55 0.8 V
SL Current V
SL
= 0V 62.4 µA
LED Current Amplitude I
LED
R
SL
= 60.4kω, V
LED
= 6.5V 9.2 10.6 12
mAR
SL
= 30.2kω, V
LED
= 6.5V 19.2 21.2 23.5
R
SL
= 30.2kω, V
LED
= 3.5V 21.2
LED Current Programmable
Range
I
RANGE
10 20 mA
LED Current with Grounded SL I
LED_MAX
V
SL
= 0V 20.6 26 31.4 mA
LED Current Frequency f
ILED
Sleep and ultra-low-power modes 250 Hz
LED Current Duty Cycle D
ILED
Sleep and ultra-low-power modes 25 %
V
DD
Current Amplitude I
VDD
Sleep mode, V
LED
= 6.5V 10 12 14.5 mA
Internal Current Duty Cycle D
IVDD
Sleep and ultra-low-power modes 75 %
Internal Current Enable Time t
MP_ENABLE
Ultra-low-power mode 76 88 98 ms
Internal Current Disable Time t
MP_DISABLE
Ultra-low-power mode 205 237 265 ms
THERMAL SHUTDOWN
Thermal Shutdown Threshold T
SD
T
J
rising 151 °C
Thermal Shutdown Hysteresis T
SD,HYS
16 °C
LDO
Input Voltage Range Inferred from line regulation 4.5 14 V
Output Voltage LDO_FB = V
DRV
3.3 V
Max Output Voltage Setting With external divider to LDO_FB 5.5 V
LDO FB Regulation Voltage 1.2 1.227 1.25 V