SPM1004

Version 3.3

February 19, 2016

Page 9 of 28

PIN DESCRIPTIONS (ALL SPM1004 Models)

PIN Name

Description

PVIN

(A3, B3, C3, D3, E3, F3, G2-G3)

Input voltage pins, referenced to PGND. Connect input ceramic capacitors between these

pins and PGND plane, close to the power module. It is suggested to place the ceramic

capacitors at both sides of the module, one between PIN A3 and PIN A4-A5 and one

between PIN G2-G3 and PIN G4-G5.

VAUX

(A1, B1)

Auxiliary output from an LDO in the module, which is referenced to AGND. An external

capacitor is not normally necessary but can be added if required.

Note: VAUX pin can only provide 1mA maximum current.

PHASE

(A6-A8)

Switching node of the Buck converter. Connect these pins together using a small and

isolated copper plane under the module for best thermal performance. Do not connect any

external component to these pins. Do not use these pins for other functions.

VOUT

(E6-E11, F6-F11, G6-G11)

Output voltage pins. Connect these pins together onto a copper plane. Connect external

output filter capacitors between these pins and PGND plane, close to the module.

PGND

(A4-A5, A9-A11, B4-B11, C4-

C11, D4-D11, E4, F4-F5, G4-

G5)

Zero DC voltage reference for power circuitry. These pins should be connected directly to

the PCB ground plane. All pins must be connected together externally with a copper plane

located directly under the module.

AGND

(A2, B2, C2)

Zero DC voltage reference for the analog control circuitry. A small analog ground plane is

recommended, and these pins should be connected directly to the PCB analog ground

plane. A single point external connection between AGND and PGND is recommended.

VADJ, SS, and VSENSE pins should be referenced to analog ground.

EN

(G1)

Enable and Under Voltage Lock Out (UVLO) pin. When floating or above Enable On Voltage

module will be off.

Different startup voltage can be programmed by an external resistor if required, as

discussed on page 18.

VADJ

(F1)

Output voltage adjustment pin. The output voltage can be adjusted up to ±10% of its

nominal value. A resistor between VADJ and VSENSE will trim the output voltage down. A

resistor between VADJ and AGND will trim the output voltage up. Refer to page 15.

VSENSE

(E1)

Remote sensing pin. Connect this pin to VOUT close to the load for improved voltage

regulation.

Note: this pin is not connected to VOUT inside the module, and must be connected

externally.

SS

(D1)

Soft-start pin. Soft-start time can be increased by connecting a capacitor between this pin

and AGND.

PWRGD

(C1)

Power Good pin, an open drain output. A resistor connected between PWRGD and VAUX

can be used as a pull-up. PWRGD is high if the output voltage is higher than 91% of the

nominal value. It will be pulled down if the output voltage is less than 80% or higher than

120% of the nominal value.