MAX5953A MAXIM [Maxim Integrated Products], MAX5953A Datasheet - Page 10

• Manufacturer Part Number: MAX5953A
• Description: IEEE 802.3af PD Interface and PWM Controllers with Integrated Power MOSFETs
• Manufacturer: MAXIM [Maxim Integrated Products]

IEEE 802.3af PD Interface and PWM Controllers
with Integrated Power MOSFETs
10
1, 2, 3, 5, 7, 12, 13, 14, 17,
(MAX5953A/MAX5953B)
(MAX5953C/MAX5953D)
(MAX5953A/MAX5953C)
(MAX5953B/MAX5953D)
19, 35, 38, 46, 47, 48
______________________________________________________________________________________
10, 11
15, 16
PIN
18
18
20
21
22
23
24
4
6
6
8
9
RCLASS
PGOOD
PGOOD
NAME
PPWM
PGND
UVLO
GATE
OUT
GND
N.C.
N.C.
CSS
V
CS
V+
EE
No Connection. Not internally connected. Make no electrical connection to these pins.
Positive Input Power. Referenced to V
Undervoltage Lockout Programming Input for PD Interface. UVLO is referenced to V
When UVLO is above its threshold, the device enters the power mode. Connect UVLO to
V
external resistor-divider between V+ and V
resistance value of the external resistors must add to 25.5kΩ (±1%) and replaces the
detection resistor. To keep the device in undervoltage lockout, drive UVLO between
V
No Connection. Not internally connected. Make no electrical connection to this pin.
Classification Setting for PD Interface. RCLASS is referenced to V
RCLASS to V
Gate of Internal Isolation n-Channel Power MOSFET. GATE is referenced to V
sources 10µA when the device enters power mode. Connect an external 100V ceramic
capacitor from GATE to OUT to program the inrush current. Drive GATE to V
the internal MOSFET. The detection and classification functions operate normally when
GATE is driven to V
Negative Input Power. Source of the integrated isolation n-channel power MOSFET.
Output Voltage. OUT is referenced to V
isolation n-channel power MOSFET. Connect OUT to GND.
Active-High, Open-Drain Power-Good Indicator Output for PD Interface. PGOOD is
referenced to OUT. PGOOD goes high impedance when V
when V
V
enable/disable the DC-DC converter.
Active-Low, Open-Drain Power-Good Indicator Output for PD Interface. PGOOD is
referenced to V
V
Current-Sense Input for PWM Controller. CS is referenced to PGND. The current-limit
threshold is internally set to 156mV relative to PGND. The device has an internal noise filter.
If necessary, connect an external RC filter from CS to PGND for additional filtering.
PWM Pulse Output. Referenced to GND. PPWM leads the internal power MOSFET pulse by
approximately 100ns.
Signal Ground of PWM Controller. Connect GND to PGND.
Power Ground of the DC-DC Converter Power Stage. Connect PGND to GND.
Soft-Start Timing Capacitor Connection for PWM Controller. CSS is referenced to GND.
Connect a 0.01µF or greater ceramic capacitor from CSS to GND. Connect to PGOOD to
automatically enable the PWM controller from the PD interface.
EE
TH,G,UVLO
OUT
GATE
to use the default undervoltage lockout threshold. Connect UVLO to the center of an
is at least 5V below V+). PGOOD can be connected directly to CSS or DCUVLO to
is 5V above V
GATE
and V
EE
is 5V above V
EE
to set a PD class (see Tables 1 and 2).
. PGOOD is pulled to V
REF,UVLO
EE
EE
.
. Otherwise, PGOOD goes high impedance.
EE
.
. Otherwise, PGOOD is internally pulled to OUT (given that
EE
EE
.
FUNCTION
EE
. OUT is connected to the drain of the integrated
EE
when V
to define a threshold externally. The series
OUT
is within 1.2V of V
OUT
is within 1.2V of V
Pin Description
EE
. Add a resistor from
EE
EE
and when
EE
to turn off
. GATE
EE
and
EE
.