MAX5945 MAXIM [Maxim Integrated Products], MAX5945 Datasheet - Page 12

• Manufacturer Part Number: MAX5945
• Description: Quad Network Power Controller for Power-Over-LAN
• Manufacturer: MAXIM [Maxim Integrated Products]

The MAX5945 four-port network power controller con-
trols -32V to -60V negative supply rail systems. Use the
MAX5945, which is compliant with the IEEE 802.3af
standard for PSE in power-over-LAN applications. The
MAX5945 provides PD discovery, classification, current
limit, both DC and AC load disconnect detections, and
other necessary functions for an IEEE 802.3af-compli-
Quad Network Power Controller
for Power-Over-LAN
Figure 1. MAX5945 Functional Diagram
12
MIDSPAN
RESET
AGND
AUTO
V
______________________________________________________________________________________
INT
A0
A1
A2
A3
EE
V
DD
SCL
MAX5945
MONITOR
ANALOG
SUPPLY
REGISTER FILE
BIAS/
INTERFACE
SERIAL
SDAIN SDAOUT
PORT
(SPI)
CENTRAL LOGIC UNIT
Detailed Description
(CLU)
+10V ANALOG
+5V DIG
CURRENT
REFERENCES
VOLTAGE
REFERENCES
SHD_
MACHINE
STATE
PORT
(SM)
OSCILLATOR
MONITOR
OPEN CIRCUIT
AC DISCONNECT
(OC)
OSC_IN
SIGNAL
(ACD)
REFERENCE
DGND
CURRENT
ACD
A = 3
DETECTION
AC
LIMIT (ILIM)
CURRENT
ant PSE. The MAX5945 can be used in either endpoint
PSE (LAN switch/router) or midspan PSE (power injec-
tor) applications.
The MAX5945 is fully software-configurable and pro-
grammable with more than 25 internal registers. The
device features an I
face and a class-overcurrent detection. The class-over-
current detection function enables system power man-
VOLTAGE PROBING
CURRENT-LIMIT
CLASSIFICATION
DETECTION/
4mV
CONTROL
ACD_ENABLE
PWR_EN
AND
SM
OVERCURRENT
CURRENT-LIMIT
(OVC)
DISCHARGE
DETECTOR
CONTROL
FAST
CONVERTER
9-BIT ADC
2
182mV
C-compatible, 3-wire serial inter-
100mA
MAX
CURRENT SENSING
90µA
10V
212mV
50µA
FOLDBACK
VOLTAGE
SENSING
13V CLAMP
CONTROL
DET_
OUT_
GATE_
SENSE_