Datasheet
SLVS167C − SEPTEMBER 1998 − REVISED − MAY 1999
21
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
APPLICATION INFORMATION
Capitalizing upon the features of the TPS73xx family (low-dropout voltage, low quiescent current, power-saving
shutdown mode, and a supply-voltage supervisor) and the power-dissipation properties of the TSSOP PowerPAD
package has enabled the integration of the TPS73HD3xx dual LDO regulator with high output current for use in DSP
and other multiple voltage applications. Figure 35 shows a typical dual-voltage DSP application.
NC
NC
1GND
1EN
1IN
1IN
NC
NC
2GND
2EN
2IN
2IN
NC
NC
1RESET
NC
NC
1FB/SENSE
1OUT
1OUT
2RESET
NC
NC
2SENSE
2OUT
2OUT
NC
NC
28
27
26
25
24
23
22
21
20
19
18
17
16
15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
C1
1 µF
U1
TPS73HD325
C2
33 µF
3.3 V
GND
R1
100 kΩ
R2
100 kΩ
5 V
PG
D3
DL5817
D1
D2
2.5 V
DL4148
C3
33 µF
CVdd
(Core
Supply)
DVdd
(I/O
Supply)
GND
VC549
DSP
+
RESET to DSP
C0
1 µF
Figure 33. Dual-Voltage DSP Application
DSP power requirements include very high transient currents that must be considered in the initial design. This design
uses higher-valued output capacitors to handle the large transient currents. Details of this type of design are shown
in the application report, Designing Power Supplies for TMS320VC549 DSP Systems.
minimum load requirements
The TPS73HD3xx is stable even at zero load; no minimum load is required for operation.