SP6654 Datasheet, PDF (3/16 Pages) Sipex Corporation – High Efficiency 800mA Synchronous Buck Regulator Ideal for portable designs powered with Li Ion battery

PIN NUMBER
1
2
3
4
5
6
7
8
9
10
PIN NAME
PV_IN
V_IN
PWR_GD
D1
D0
FB
V_OUT
GND
P_GND
LX
PIN DESCRIPTION
DESCRIPTION
Input voltage power pin. Inductor charging current passes through this pin.
Internal supply voltage. Control circuitry powered from this pin.
Open drain Power Good indicator. If V_FB is less than 750mV this pin is
pulled to ground. When V_FB is above 750mV this pin is open. Connect
a resistor from this pin to V_IN or V_OUT to create a logic signal.
Digital mode control input. See table I for definition.
Digital mode control input. See table I for definition.
External feedback network input connection. Connect a resistor from
FB to ground and FB to V_OUT to set the output voltage. This pin
regulates to the internal bandgap reference voltage of 0.8V.
Output voltage sense pin. Used by the timing circuit to set minimum on
and off times.
Internal ground pin. Control circuitry returns current to this pin.
Power ground pin. Synchronous rectifier current returns through this pin.
Inductor switching node. Inductor tied between this pin and the output
capacitor to create regulated output voltage.
D1
D0
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
Table 1. Operating Mode Definition
FUNCTIONAL DIAGRAM
DRVON
VOLOW
TONOVER
MIN Ton
REF
+^Vos-^REF'
VOLOW
+
C
V_RAMP
-
FB ⁺
- ^FB'
RST
DRVON
OVR_I
Vin
V_OUT
Internal Supply
TONOVER Min Ton
Min Ton = K_ON/(V_IN -V_OUT)
R
Q
_
S
Q
DRVON
DRIVER
PV_IN
M
1
+
ILIM/M
C
-
OVR_I
LX
D0
Ref
REF
UVLO
Block TSD
D1
ILIM/M
GND
BLANK
One-Shot
=100ns
T_OFF =
K_OFF/V_OUT
DRVON
BLANK
BLANK = Tblank(=100ns) or Toff = Koff/Vout
OVR_I
750mV
FB
+
C
-
UVLO
+
Zero_X
C
-
P_GND
PWR_GD
Date: 05/25/04
SP6654 High Efficiency 800mA Synchronous Buck Regulator
3
© Copyright 2004 Sipex Corporation