MAX5953DUTM+【PDF 11/27 页】IC INTERFACE 802.3AF 48TQFN

收藏本站

您好，
买卖IC网欢迎您。
请登录
免费注册

买卖IC网

Sheet目录43

7页 8页 9页 10页 [11页]12页 13页 14页 15页

IEEE 802.3af PD Interface and PWM Controllers

with Integrated Power MOSFETs

______________________________________________________________________________________ 11

Pin Description (continued)

NAME

FUNCTION

OPTO

PWM Comparator Inverting Input. OPTO is referenced to GND. Connect the collector of the

optotransistor to OPTO and a pullup resistor to REGOUT.

26, 27

SRC

Source Connection of Low-Side Power MOSFET in the Two-Switch Power Stage of the DC-

DC Converter. Connect SRC to PGND with a low-value resistor for current limiting.

28, 29

XFRMRL

Low-Side Connection for the Isolation Transformer. Drain terminal of low-side power

MOSFET in the two-switch power stage of the DC-DC converter.

DRVIN

Supply Input for the Gate-Driver of Internal Power MOSFETs. DRVIN is referenced to

PGND. Bypass DRVIN with at least 0.1礔 to PGND. Connect DRVIN to REGOUT.

31, 32

XFRMRH

High-Side Connection for the Isolation Transformer. Source connection of high-side power

MOSFET in the two-switch power stage of the DC-DC converter.

33, 34

DRNH

Drain Connection of High-Side MOSFET in the Two-Switch Power Stage of the DC-DC

Converter. Connect DRNH to the most positive rail of the input supply. Bypass DRNH

appropriately to handle the heavy switching current through the transformer.

BST

Boost Input for the DC-DC Converter. BST is the boost connection point for the high-side

MOSFET driver. Connect a minimum 0.1礔 capacitor from BST to XFRMRH with short and

wide PC board traces.

DCUVLO

DC-DC Converter Undervoltage Lockout Input. DCUVLO is referenced to GND. Connect a

resistor-divider from HVIN to DCUVLO to GND to set the UVLO threshold.

HVIN

DC-DC Converter Positive Input Power Supply. HVIN is referenced to GND. Connect HVIN

to V+.

INBIAS

Input from the Rectified Bias Winding to the DC-DC Converter. INBIAS is referenced to

GND. INBIAS is the input to the internal linear voltage regulator (REGOUT).

REGOUT

Internal Regulator Output. REGOUT is used for the DC-DC converter gate driver. REGOUT

is referenced to GND. V

REGOUT

is always present as long as HVIN is powered with a

voltage above the DCUVLO threshold. Bypass REGOUT to GND with a minimum 2.2礔

ceramic capacitor.

RTCT

Oscillator Frequency Set Input for the PWM Controller. RTCT is referenced to GND.

Connect a resistor from RTCT to REGOUT and a ceramic capacitor from RTCT to GND to

set the oscillator frequency.

FLTINT

Fault Integration Input for PWM Controller. FLTINT is referenced to GND. During persistent

current-limit faults, a capacitor connected to FLTINT is charged with an internal 80礎

current source. Switching is terminated when V

FLTINT

reaches 2.7V. An external resistor

connected in parallel discharges the capacitor. Switching resumes when V

FLTINT

drops

to 1.9V.

RCFF

Feed-Forward Input for PWM Controller. RCFF is referenced to GND. To generate the PWM

ramp, connect a resistor from RCFF to HVIN and a capacitor from RCFF to GND.

RAMP

Ramp Sense Input for PWM Controller. Connect RAMP to RCFF.

Exposed Paddle. EP is internally unconnected and must be connected to V

externally.

To improve power dissipation, solder the exposed paddle to a copper pad on the PC

board.

发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

*型号	*数量	厂商	批号	封装

添加更多采购

采购需求

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

我的联系方式