Data Sheet

LT4322

analog.com

Rev. 0

6 of 29

PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS

Figure 3. DDM8 Package 8-Lead, 3mm × 3mm Plastic Side Wettable DFN. TJMAX = 150°C, JA = 43°C/W. Exposed Pad (Pin 9) PCB

Connection to VSSA is Optional

Figure 4. MS8 Package 8-Lead, Plastic MSOP. TJMAX = 150°C, JA = 163°C/W

Table 3. Pin Descriptions

PIN

NAME

DESCRIPTION

DDM

Package

Only

Exposed Pad Exposed pad can be left open or connected to the device ground (VSSA).

Pin 1

GATE

GATE Drive Output. The LT4322 controls the gate of an external N-Channel MOSFET to

regulate the ANODE-to-CATHODE voltage drop to 25mV. If a reverse ANODE-to-

CATHODE voltage is detected, a fast pull-down circuit connects GATE to VSSA within

150ns, turning off the MOSFET. If the forward drop voltage exceeds 30mV, a fast pull-

up circuit connects GATE to VDDA within 1µs, turning on the MOSFET hard. Connect to

the gate of the external MOSFET.

Pin 2

VSSA

Device Ground. This is the ground reference for the LT4322. Connect to the source of

the external MOSFET.

Pin 3

ANODE

External MOSFET Source Voltage Kelvin Sense Input. Connect to the source of the

external MOSFET.

Pin 4

VDDA

LDO Supply Voltage Output or Power Supply Input. The LT4322 is powered from the

VDDA pin. The voltage on VDDA sets the maximum GATE drive voltage. When VDDA derives

power from VDDC, a 1µF or larger hold-up capacitor is required to maintain the VDDA

voltage during the portion of the AC waveform when the VDDC voltage is lower than VDDA.

See the VDDA Capacitor Selection section for guidance in selecting the capacitor value.

When powering VDDA directly from a DC power supply, ensure the supply voltage is

1

2

3

4

VSSA

ANODE

VDDA

GATE

8

7

6

5

NC

NC

CATHODE

VDDC

LT4322

(Not to Scale)

TOP VIEW

NOTES

1. NC = NO CONNECT. DO NOT

CONNECT TO THIS PIN.