
SWCS037G
– MAY 2008 – REVISED APRIL 2011
4.1.2
VDD2 dc-dc Regulator
4.1.2.1
VDD2 dc-dc Regulator Characteristics
The VDD2 dc-dc regulator is a programmable output stepdown dc-dc converter with an internal field effect
transistor (FET). Like the VDD1 regulator, the VDD2 regulator can be placed in sleep or power-down
mode and is SmartReflex-compatible. The VDD2 regulator differs from VDD1 in its current load capability.
Table 4-4 describes the regulator characteristics.
Table 4-4. VDD2 dc-dc Regulator Characteristics
Parameter
Comments
Min
Typ
Max
Unit
Input voltage range
2.7
3.6
4.5
V
Output voltage
0.6
1
1.5
V
Output voltage step
Covering the 0.6-V to 1.45-V range,
12.5
mV
1.5 V is a single programmable value
Output accuracy(1)
0.6 V to
< 0.8 V
–6%
6%
0.8 V to 1.5 V
–4%
4%
Switching frequency
3.2
MHz
IO = 10 mA, sleep
82%
Conversion efficiency(2), Figure 4-4 in active mode 100 mA
< IO < 300 mA
85%
300 mA
< IO < 500 mA
80%
Active mode
600
mA
Output current
Sleep mode
10
mA
Ground current (IQ)
Off at 30
°C
1
μA
Sleep, unloaded
50
Active, unloaded, not switching
300
Short-circuit current
VIN = VMax
1.2
A
Load regulation
0
< IO < IMax
20
mV
IO = 10 mA to (IMax/2) + 10 mA,
Transient load regulation(3)
–65
50
mV
Maximum slew rate is IMax/2/100 ns
Line regulation
10
mV
Transient line regulation
300 mVPP ac input, 10-μs rise and fall
10
mV
time
Output shunt resistor (internal pulldown)
500
700
Start-up time
0.25
1
ms
Recovery time
From sleep mode to on mode with
25
100
μs
constant load
Slew rate (rising or falling)(4)
4
8
16
mV/
μs
Value
0.7
1
1.3
μH
External coil
DCR
0.1
Saturation current
900
mA
Value
8
10
12
μF
External capacitor(5)
ESR at switching frequency
0
20
m
(1)
Accuracy includes all variations (line and load regulations, line and load transients, temperature, and process)
(2)
VBAT = 3.8 V, VDD2 = 1.3 V, Fs = 3.2 MHz, L = 1
μH, LDCR = 100 m, C = 10 μF, ESR = 10 m
(3)
Output voltage needs to discharge the load current completely and settle to its final value within 100
μs.
(4)
Load current varies proportionally with the output voltage. The slew rate is for both increasing and decreasing voltages and the
maximum load current is 600 mA.
(5)
Under current load condition step:
Imax/2 (300 mA) in 100 ns with a
±20% external capacitor accuracy or
Imax/3 (200 mA) in 100 ns with a
±50% external capacitor accuracy
32
Power Module
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2008–2011, Texas Instruments Incorporated