tda3602-n3 NXP Semiconductors, tda3602-n3 Datasheet - Page 13

• Manufacturer Part Number: tda3602-n3
• Description: Multiple Output Voltage Regulator
• Manufacturer: NXP Semiconductors

Philips Semiconductors
APPLICATION INFORMATION
Noise
Table 3 Noise at regulator outputs dependent on
Note
1. Regulators loaded with 100mA; noise in V RMS
The available noise at the output of the regulators depends
on the bandwidth of the regulators, which can be adjusted
by means of the load capacitors. The noise figures are
given in Table 3.
Although stability is guarenteed when C
10 F (over temperature range) with tan ( ) = 1 in the
frequency range 1 kHz to 20 kHz, it is recommended to
use a 47 F load capacitor for Regulators 1 and 2. When
a microprocessor is supplied by Regulator 3 much noise
can be produced by this microprocessor. This noise is not
influenced by increasing the load capacitor of Regulator 3.
The noise on the supply line depends on the supply
capacitor. When a high frequency capacitor of 220 nF with
an electrolytic capacitor of 100 F in parallel is placed
directly over pin 1 (V
minimized.
The stabilizer is in 'power on' after the supply is
reconnected (V
Application circuits
S
The low end application is illustrated in Fig.7. When switch
SW1 is closed, a pulse is generated at the state control
input by C5 and R1, and the regulator is switched from
power off to the on mode (all three regulators are on). The
HOLD signal can be used to control the mute signal for the
power amplifiers. This signal is HIGH when all the
regulators are in regulation and V
July 1994
TABILIZER WITHOUT MICROPROCESSOR
Multiple output voltage regulator
REG
(B = 10 Hz to 1 MHz).
REGULATOR
1
2
3
(NOTE 1)
capacitive load (C
150 mA
100 mA
50 mA
bu
I
L
> 7.9 V) and 0.1 < V
P
) and pin 6 (ground) the noise is
800 V
500 V
350 V
10 F
L
).
P1
Schmitt trigger is true.
220 V
190 V
115 V
47 F
sc
1
C
L
< 2.2 V.
L
is higher than
220 F
160 V
13
S
Fig.8 illustrates the application circuit for a low end radio
set with push switches when no microprocessor is used.
The stabilizer can be switched to the on mode by pressing
switch SW1. In this mode, Regulators 1 and 2 are switched
on, so transistor T1 takes over from switch SW1. The
stabilizer can only be switched off by connecting the base
of T1 to ground (SW1 not pressed). This can be achieved
by pressing switch SW2.
The hold signal is only HIGH when the device is in the on
mode and both V
this signal can be used to control the power stages (mute).
During a fault condition, this signal turns LOW
immediately.
When the stabilizer is connected to the supply for the first
time, the initial state will be the power-on stage, so
Regulators 1 and 2 are not switched on.
S
For a good understanding of the high end application,
shown in Fig.10, consult the flow chart of Fig.9.
When the set is off, a reset can be generated by
connecting the set to the supply for the first time (stabilizer
in power-on), or by pressing any key on the key matrix
(stabilizer in reset mode). When the reset is generated, the
stabilizer is held in the reset mode for a short period by T1.
The microprocessor has to take over control by making
reset mode equal to 0. The microprocessor can then
proceed with the initializing process. After this action, the
microprocessor has to check if the correct key has been
pressed. If so, the radio can be switched on by making on
equal to 0; if not, the microprocessor must switch the
device to the coma mode again, by making reset mode
and on both equal to 1; (wake mode is entered after a short
time constant, determined by R1
switch itself to sleep mode.
When the reset is generated for the first time (power-on
mode), the mode of the device can be detected by the hold
signal. If on = 0 and hold remains LOW, then the
microprocessor is in the power-on mode. In this event, the
microprocessor must go to the switch-off routine (making
on and reset mode both equal to 1).
TABILIZER WITHOUT MICROPROCESSOR
TABILIZER USED WITH MICROPROCESSOR
P
and the regulators are available, so that
C7
Product specification
2
constant), and
TDA3602