2

FIGURE 2. SP6654 1.5V OUTPUT EVALUATION BOARD SCHEMATIC

COUT

22uF

CIN

22uF

CVIN

1.0uF

1

Vout 1.5V 800mA

PWRGD

D0

L1

10uH

SP6654

U1

PVin

1

Vin

2

PWRGD

3

D1

4

D0

5

FB

6

Vout

7

GND

8

PGND

9

LX

10

RVIN

10.0

Vin 2.7 - 5.5VDC

CF

22pF

3

RI

261K

1

2

3

D1

RF

226K

2

USING THE EVALUATION BOARD

1) Powering up the SP6654 Circuit & Programming the UVLO threshold

The SP6654 Evaluation Board can be powered from a single Li-Ion battery or a +2.7 to

+5.5V power supply. Connect with short leads directly to the “Vin” and “Gnd” posts.

Note the SP6654 will remain in “shutdown” until D0 or D1 of the Jumpers J1 or J2 are

applied to the Vin or position 1 to 2. See Table 1 for UVLO threshold programming and

D1 and D0 pin definition.

Table 1. Operating Mode Definition

D1

D0

Definition

0

0

Shutdown. All internal circuitry is disabled and the power switches are opened.

0

1

Device enabled, falling UVLO threshold = 2.70V

1

0

Device enabled, falling UVLO threshold = 2.85V

1

1

Device enabled, falling UVLO threshold = 3.00V

2) VOUT PROGRAMMING

The SP6654 requires 2 feedback resistors to control the output voltage. Connect the

appropriate resistors RF and RI (Table 2) from pin 6 SP6654 FB to Vout and to the

GND.

For Vout different from that shown in the Table 2, use equation:

RI

Vout

RF

•













−

=

1

8

.

0