PTH03060Y
PTH05060Y, PTH12060Y
www.ti.com
SLTS222A – MARCH 2004 – REVISED OCTOBER 2005
APPLICATION INFORMATION
Typical DDR Application Diagram
Auto-Track
V
I
= 5V
+
470
µF
47
µF
V
I
Inhibit
5.51 kΩ
Margin
±
+Sense
V
O
+V
ADJ
+
2
×
330
µF
2
×
22
µF
V
DDQ
= 1.8 V
PTH05010W
VDDQ I/O Memory
DDRII/
QDRII
V
I
+
Inhibit
PTH05050Y
DDR Termination
V
TT
+V
REF
+
2
×
330
µF
V
TT
= 0.9 V
2
×
22
µF
1 kΩ
220
µF
47
µF
1 kΩ
UDG−05096
CAPACITOR RECOMMENDATIONS FOR THE PTH03060Y AND PTH05060Y DDR POWER
MODULES (3.3-V/5-V OPTION)
Input Capacitor
The recommended input capacitor(s) is determined by the 330
µF
(1)
minimum capacitance and 300 mArms
minimum ripple current rating.
Ripple current and less than 160 mΩ equivalent series resistance (ESR) values are the major considerations,
along with temperature, when designing with different types of capacitors. Unlike polymer tantalum, regular
tantalum capacitors have a recommended minimum voltage rating of 2
×
(maximum DC voltage + AC ripple).
This is standard practice to insure reliability.
For improved ripple reduction on the input bus, ceramic capacitors may be substituted for electrolytic types using
the minimum required capacitance.
Output Capacitors
For applications with load transients (sudden changes in load current), regulator response will benefit from
external output capacitance. The recommended output capacitance of 470
µF
will allow the module to meet its
transient response specification (see Electrical Specifications table). For most applications, a high quality
computer-grade aluminum electrolytic capacitor is adequate. These capacitors provide decoupling over the
frequency range, 2 kHz to 150 kHz, and are suitable when ambient temperatures are above 0°C. For operation
below 0°C tantalum, ceramic or Os-Con type capacitors are recommended. When using one or more
non-ceramic capacitors, the calculated equivalent ESR should be no lower than 4 mΩ (7 mΩ using the
manufacturer's maximum ESR for a single capacitor). A list of preferred low-ESR type capacitors are identified in
Table 1.
7
TI [ TEXAS INSTRUMENTS ]
