
RT9173/A
5
DS9173/A-18 March 2007
www.richtek.com
Absolute Maximum Ratings
z
Input Voltage------------------------------------------------------------------------------------------------------------ 7V
z
Power Dissipation ----------------------------------------------------------------------------------------------------- Internally Limited
z
ESD Rating ------------------------------------------------------------------------------------------------------------- 2kV
z
Storage Temperature Range ----------------------------------------------------------------------------------------
65
°
C to 150
°
C
z
Lead Temperature (Soldering, 10 sec.)--------------------------------------------------------------------------- 260
°
C
z
Power Dissipation, P
D
@ T
A
= 25
°
C
TO-263-5----------------------------------------------------------------------------------------------------------------- 1.923W
TO-252-5----------------------------------------------------------------------------------------------------------------- 1.471W
SOP-8-------------------------------------------------------------------------------------------------------------------- 0.625W
z
Package Thermal Resistance (Note 3)
TO-263-5,
θ
JC
---------------------------------------------------------------------------------------------------------- 7.7
°
C/W
TO-252-5,
θ
JC
---------------------------------------------------------------------------------------------------------- 8
°
C/W
SOP-8,
θ
JC
-------------------------------------------------------------------------------------------------------------- 23.2
°
C /W
TO-263-5,
θ
JA
------------------------------------------------------------------------------------------------------------ 52
°
C/W
TO-252-5,
θ
JA
----------------------------------------------------------------------------------------------------------- 68
°
C/W
SOP-8,
θ
JA
-------------------------------------------------------------------------------------------------------------- 160
°
C/W
Electrical Characteristics
(V
IN
= 2.5V, V
CNTL
= 3.3V, V
REFEN
= 1.25V, C
OUT
= 10
μ
F (Ceramic), T
A
= 25
°
C, unless otherwise specified.)
Parameter
Symbol
Test Conditions
Min
Typ
Max Units
Output Offset Voltage
V
OS
I
OUT
= 0A, Figure 1 (Note 1)
I
L
: 0A
→
1.5A, Figure 1
I
L
: 0A
→
-1.5A
Keep V
CNTL
≥
V
IN
on operation power
on and power off sequences
-20
0
20
mV
--
0.8/1.2
2/3
Load Regulation (DDR 1/2)
Δ
V
LOAD
--
0.8/1.2
2/3
%
V
IN
V
CNTL
I
CNTL
I
SHDN
1.6
2.5/1.8
--
Input Voltage Range (DDR 1/2)
(Note 2)
--
3.3
6
V
Operating Current of VCNTL
No Load
V
REFEN
<
0.2V, R
L
= 180
Ω
, Figure 2
--
6.5
10
mA
μ
A
Current In Shutdown Mode
--
50
90
Short Circuit Protection
Current limit
I
LIMIT
Figure 3,4
3.0
--
--
A
Over Temperature Protection
Thermal Shutdown Temperature T
SD
Thermal Shutdown Hysteresis
3.3V
≤
V
CNTL
≤
5V
Guaranteed by design
125
150
--
°
C
°
C
--
50
--
Shutdown Function
V
TRIGGER
Output = High, Figure 5
V
TRIGGER
Output = Low, Figure 5
0.8
--
--
Shutdown Threshold Trigger
--
--
0.2
V
Note 1.
V
OS
offset is the voltage measurement defined as V
OUT
subtracted from V
REFEN
.
Note 2.
For safely operate your system, the 3.3V rail MUST be tied to V
CNTL
rather than 5V rail, especially for the new part of
RT9173ACL5.
Note 3.
θ
JA
is measured in the natural convection at T
A
= 25
°
C on a low effective thermal conductivity test board (single Layers,
1S) of JEDEC 51-3 thermal measurement standard. The case point of
θ
JC
is on the on the center of V
CTRL
pins (Lead
6 & 7) for SOP-8 packages, the center of heat sink (tab) for TO-252-5 and TO-263-5 packages.