TDA3603 Datasheet, PDF (13/20 Pages) NXP Semiconductors – Multiple voltage regulator with switch

Philips Semiconductors
Multiple voltage regulator with switch
TEST AND APPLICATION INFORMATION
Product specification
TDA3603
ndbook, full pagewidth
Vsw
9
VP
Ven
VI(ig)
C1 ⁽¹⁾
220 nF
VP
1
R1
1 kΩ
enable input
4
TDA3603
ignition input
8
regulator 2
7
regulator 1
2
47 kΩ
R2
reset
output
3
ignition
output
5
6
ground
C2
10 µF
5V
C3
10 µF
8.5 V
C4
10 µF
C5
1 µF
MBE232
R _L(sw)
1 kΩ
R _L(REG2)
1 kΩ
R _L(REG1)
1 kΩ
(1) Capacitor not required for stability.
Fig.7 Test circuit (for SOT110-1).
Noise information
The noise at the output of the regulators depends on the
bandwidth of the regulators, which can be adjusted by the
output capacitors. Table 1 shows the noise figures.
Although stability is guaranteed when C_L is higher than
10 µF (over temperature range) with tan (φ) = 1 in the
frequency range 1 to 10 kHz, however, for low noise, a
47 µF load capacitor is required. When electrolytic
capacitors are used, the capacitor value will decrease and
the ESR will increase much at low temperatures. To avoid
oscillation a normal capacitor of 220 nF can be placed in
parallel with this electrolytic capacitor.
The noise on the supply line depends on the value of the
supply capacitor and is caused by a current noise (output
noise of the regulators is translated into a current noise by
the output capacitors). When a high frequency capacitor of
220 nF with an electrolytic capacitor of 100 µF in parallel is
placed directly over pins 1 and 6 (supply and ground) the
noise is minimized.
Table 1 Noise figures
REGULATOR NOISE (µV)⁽¹⁾
180
1
100
80
120
2
70
70
Note
1. Bandwidth of 100 kHz.
OUTPUT
CAPACITOR (µF)
10
47
100
10
47
100
1997 Aug 15
13