MAX5971A Maxim Integrated Products, MAX5971A Datasheet - Page 12

• Manufacturer Part Number: MAX5971A
• Description: Single-Port 40W IEEE 802.3af/at PSE Controller with Integrated MOSFET
• Manufacturer: Maxim Integrated Products

Single-Port, 40W, IEEE 802.3af/802.3at PSE
Controller with Integrated MOSFET
12
16, 18, 20,
22, 24, 28
26, 27
_____________________________________________________________________________________
PIN
13
14
17
19
21
23
25
—
LEGACY
NAME
AGND
OUTP
OSC
N.C.
OUT
LED
DET
EN
EP
Legacy Detection Logic Input. Referenced to V
supply. Leave unconnected to activate the legacy PD detection. Force low to disable this function.
The LEGACY logic level latches after the device is powered up or after a reset condition.
Enable Input. Referenced to V
nected to enable the device. Force low for at least 40Fs to reset the device. The MIDSPAN, OSC,
and LEGACY states latch-in when the reset condition is removed (low-to-high transition).
No Connection. Not internally connected. Leave N.C. unconnected.
LED Indicator Open-Drain Output. Referenced to V
nal LED directly. Blinking functionality is provided to signal different conditions (see the PWM and
LED Signals section). Connect LED to AGND externally (see Figures 6 and 7) or to an external
supply (if available) through a series resistance.
AC-Disconnect Triangular Wave Output. Bypass with a 100nF (Q10% tolerance) external capacitor
to V
function and to activate the DC disconnect function. The OSC state latches after the device is
powered up or after a reset condition.
High-Side Supply Input
Detection/Classification Voltage Output. DET is used to set the detection mark event and clas-
sification probe voltages and for the AC current sensing when using the AC disconnect function.
To use the AC disconnect function, place a 1kI and 0.47FF RC series in parallel with the external
protection diode to OUTP (see Figure 7).
Port Pullup Output. OUTP is used to pull up the port voltage to AGND when needed. If AC discon-
nect is used, connect OUTP to the anode of the AC-blocking diode. If AC disconnect is not used,
connect OUTP to OUT (see Figures 6 and 8). Bypass OUTP to AGND with a 100V, 0.1FF ceramic
capacitor.
Integrated MOSFET Output. If DC disconnect is used, connect the port output to OUT (see Figures
6 and 8). If the AC disconnect function is used, connect OUT to the cathode of the AC-blocking
diode (see Figure 7).
Exposed Pad. Connect EP to V
EE
to enable the AC disconnect function. Connect OSC to V
EE
EE
. EN is internally pulled up to the digital supply. Leave uncon-
externally. See the Layout Procedure section for details.
FUNCTION
EE
. LEGACY is internally pulled up to the digital
EE
Pin Description (continued)
. LED can sink 10mA and can drive an exter-
EE
to disable the AC disconnect