SP6654EB Datasheet, PDF (2/4 Pages) Sipex Corporation – Evaluation Board Manual

FIGURE 2. SP6654 1.5V OUTPUT EVALUATION BOARD SCHEMATIC
Vin 2.7 - 5.5VDC
PWRGD
1
D1
2
3
1
D0
2
3
RVIN
10.0
CIN
22uF
U1 SP6654
1
PVin
10
LX
2 _{Vin PGND} 9
3
8
PWRGD GND
4 _D1
Vout ⁷
5 _D0
FB ⁶
CVIN
1.0uF
L1 _10uH
Vout 1.5V 800mA
CF
22pF
RF
226K
RI
261K
COUT
22uF
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:
RF
=


Vout
0.8
−1 • RI

2