ADP1610ARMZ-R7(Rev0) View Datasheet(PDF) - Analog Devices
Part Name
Description
Manufacturer
ADP1610ARMZ-R7 Datasheet PDF : 16 Pages
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ADP1610
Table 7. Recommended External Components for Popular Input/Output Voltage Conditions
VIN (V) VOUT (V) fSW (MHz) L (µH) COUT (µF) CIN (µF) R1 (kΩ) R2 (kΩ) RComp (kΩ)
3.3
5
0.700
4.7
10
10
30.9
10
50
5
1.23
2.7
10
10
30.9
10
90.9
9
0.700
10
10
10
63.4
10
71.5
9
1.23
4.7
10
10
63.4
10
150
12
0.700
10
10
10
88.7
10
130
12
1.23
4.7
10
10
88.7
10
280
5
9
0.700
10
10
10
63.4
10
84.5
9
1.23
4.7
10
10
63.4
10
178
12
0.700
10
10
10
88.7
10
140
12
1.23
4.7
10
10
88.7
10
300
Ccomp (pF)
520
150
820
180
420
100
390
100
220
100
IOUT_MAX (mA)
600
600
350
350
250
250
450
450
350
350
REF
FB 2
ERROR AMP
gm
COMP
1
RC
C2
CC
Figure 26. Compensation Components
The capacitor, C2, is chosen to cancel the zero introduced by
output capacitance ESR.
Solving for C2,
C2 = ESR ×COUT
(19)
RCOMP
For low ESR output capacitance such as with a ceramic capaci-
tor, C2 is optional. For optimal transient performance, the RCOMP
and CCOMP might need to be adjusted by observing the load
transient response of the ADP1610. For most applications, the
compensation resistor should be in the range of 30 kΩ to
400 kΩ, and the compensation capacitor should be in the range
of 100 pF to 1.2 nF. Table 7 shows external component values
for several applications.
SOFT START CAPACITOR
The voltage at SS ramps up slowly by charging the soft start
capacitor (CSS) with an internal 3 µA current source. Table 8
listed the values for the soft start period, based on maximum
output current and maximum switching frequency.
The soft start capacitor limits the rate of voltage rise on the
COMP pin, which in turn limits the peak switch current at
startup. Table 8 shows a typical soft start period, tSS, at
maximum output current, IOUT_MAX, for several conditions.
A 20 nF soft start capacitor results in negligible input current
overshoot at startup, and so is suitable for most applications.
However, if an unusually large output capacitor is used, a longer
soft start period is required to prevent input inrush current.
Table 8. Typical Soft Start Period
VIN (V)
VOUT (V)
COUT (µF)
3.3
5
10
5
10
9
10
9
10
12
10
12
10
5
9
10
9
10
12
10
12
10
CSS (nF)
20
100
20
100
20
100
20
100
20
100
tSS (ms)
0.3
2
2.5
8.2
3.5
15
0.4
1.5
0.62
2
Conversely, if fast startup is a requirement, the soft start
capacitor can be reduced or even removed, allowing the
ADP1610 to start quickly, but allowing greater peak switch
current (see Figure 22 to Figure 25).
APPLICATION CIRCUITS
The circuit in Figure 27 shows the ADP1610 in a step-up
configuration. The ADP1610 is used here to generate a 10 V
regulator with the following specifications: VIN = 2.5 V to 5.5 V,
VOUT = 10 V, and IOUT ≤ 400 mA.
4.7µH
3.3V
CIN
10µF
L
ADP1610
6 IN
SW 5
ON
3 SD
7 RT
FB 2
CSS
22nF
8 SS
COMP 1
GND
4
D1
R1
71.3kΩ
R2
10kΩ
RCOMP
220kΩ
CCOMP
150pF
10V
COUT
10µF
Figure 27. 3.3 V to 10 V Step-Up Regulator
The output can be set to the desired voltage using Equation 2.
Use Equation 16 and 17 to change the compensation network.
Rev. 0 | Page 13 of 16
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