AIC1571 Datasheet, PDF (12/18 Pages) Analog Intergrations Corporation – 5-bit DAC, Synchronous PWM Power Regulator with Dual Linear Controllers

AIC1571
table.
3. Determine I_PEAK > I_OUT(MAX) + (inductor ripple
current) /2.
PWM OUT1 Voltage Program
The output voltage of the PWM converter is
programmed to discrete levels between 1.3V to
3.5V. The VID pins program an internal voltage
reference (DACOUT) through a TTL compati-
ble 5 bit digital to analog converter. The VID
pins can be left open for a logic 1 input, be-
cause they are internally pulled up to 5V by a
70kΩ resistor. Changing the VID inputs during
operation is not recommended. All VID pin
combinations resulting in an INHIBIT disable
the IC and the open collector at the PGOOD
pin.
Shutdown
Holding the SS pin low with an open drain or
collector signal turns off all three regulators.
The VID codes resulting in an INHIBIT as
shown in Table 1 also shut down the IC.
Table 1 V_OUT1 Voltage Program (0=connected to GND, 1=open or connected to 5V)
VID4
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
PIN NAME
VID3 VID2 VID1
1
1
1
1
1
1
1
1
0
1
1
0
1
0
1
1
0
1
1
0
0
1
0
0
0
1
1
0
1
1
0
1
0
0
1
0
0
0
1
0
0
1
0
0
0
0
0
0
VID0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
For all package version
DACOUT
PIN NAME
VOLTAGE VID4 VID3 VID2 VID1
1.30V
1
1
1
1
1.35V
1
1
1
1
1.40V
1
1
1
0
1.45V
1
1
1
0
1.50V
1
1
0
1
1.55V
1
1
0
1
1.60V
1
1
0
0
1.65V
1
1
0
0
1.70V
1
0
1
1
1.75V
1
0
1
1
1.80 V
1
0
1
0
1.85 V
1
0
1
0
1.90 V
1
0
0
1
1.95 V
1
0
0
1
2.00 V
1
0
0
0
2.05 V
1
0
0
0
VID0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
DACOUT
VOLTAGE
INHIBIT
2.1 V
2.2 V
2.3 V
2.4 V
2.5 V
2.6 V
2.7 V
2.8 V
2.9 V
3.0 V
3.1 V
3.2 V
3.3 V
3.4 V
3.5 V
Layout Considerations
Any inductance in the switched current path
generates a large voltage spike during the
switching interval. The voltage spikes can de-
grade efficiency, radiate noise into the circuit,
and lead to device over-voltage stress. Careful
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