STHS2377A datasheet(7/20 Pages) STMICROELECTRONICS

7 / 20 page

STHS237x

Summary description

7/20

1.1

Pin descriptions

1.1.1

Current limit (ILIM)

Connect a resistor between ILIM and VSS to set the start-up inrush current limit.

ILIM = 25 000/RILIM [A]. Practical values of RILIM are between 62.5kΩ and 500kΩ.

RILIM = 178kΩ for inrush current of 140mA for compatibility with legacy PSEs. Do not leave

open or connect to VSS.

1.1.2

Classification (CLASS)

Connect a Classification resistor between this pin and VSS to tell the PSE which power class

will be connected. Do not connect this pin directly to VSS.

For classification resistor values, see Table 3 on page 8.

1.1.3

Detection resistor (DET)

Connect a 24.9k

Ω resistor between DET and VDD to allow the PSE to detect the Powered

Device properly.

1.1.4

Ground (VSS)

This is the return power line on the PSE side (negative).

1.1.5

Return (RTN)

This is the return power output on the load side, negative rail.

1.1.6

Power Good output (PG)

This pin indicates that the STHS power MOSFET is fully on and works in normal operation

mode (Power Good). Open drain, high impedance means that the power is good; in all other

cases, the impedance is low (referenced to RTN).

1.1.7

Undervoltage Lockout Input (UVLO, STHS2376A/L only)

Connect the tap of the resistor divider between VDD and VSS to set the UVLO voltage limits

(see Figure 6 on page 10).

Note: STHS2376A/L only, for all other devices, this is No Connect.

1.1.8

Power supply (VDD)

This is the Power Input/Output, positive rail.

STHS2377A Datasheet(PDF) 7 Page - STMicroelectronics