CS5258-1
CS5258-1
8A LDO 5-Pin Adjustable Linear Regulator
Description
This new very low dropout regula-
tor is designed to power the next
generation of advanced microproces-
sors. To achieve very low dropout,
the internal pass transistor is pow-
ered separately from the control cir-
cuitry. Furthermore, with the control
and power inputs tied together, this
device can be used in single supply
configuration and still offer a better
dropout voltage than conventional
PNP-NPN based LDO regulators. In
this mode the dropout is determined
by the minimum control voltage.
It is supplied in a five-terminal TO-
220 package, which allows for the
implementation of a remote-sense
pin permitting very accurate regula-
tion of output voltage directly at the
load, where it counts, rather than at
the regulator. This remote sensing
feature virtually eliminates output
voltage variations due to load
changes and resistive voltage drops.
Typical load regulation measured at
the sense pin is 1mV for an output
voltage of 2.5V with a load step of
10mA to 8A.
The very fast transient loop response
easily meets the needs of the latest
microprocessors. In addition, a small
capacitor on the Adjust pin will fur-
ther improve the transient capabili-
ties.
Internal protection circuitry pro-
vides for Òbust-proofÓ operation,
similar to three-terminal regulators.
This circuitry, which includes over-
current, short circuit, supply
sequencing and overtemperature
protection, will self protect the regu-
lator under all fault conditions.
The CS5258-1 is ideal for generating
a secondary 2 - 2.5V low voltage
supply on a motherboard where
both 5V and 3.3V are already
available.
Features
s
1.25V to 5V V
OUT
at 8A
s
V
POWER
Dropout <0.4V @ 8A
s
V
CONTROL
Dropout <1.15V @
8A
s
1.5% Trimmed Reference
s
Fast Transient Response
s
Remote Voltage Sensing
s
Thermal Shutdown
s
Current Limit
s
Short Circuit Protection
s
Backwards Compatible with
3-pin Regulators
Package Options
5 Lead TO-220
Applications Diagram
5.0V
V
CONTROL
V
OUT
CS5258-1
2.5V@8A
3.3V
V
POWER
V
SENSE
Adjust
124
1%
124 Load
1%
300mF
5V
1
1. V
SENSE
2. Adjust
3. V
OUT
4. V
CONTROL
5. V
POWER
Tab = V
OUT
10mF
10V
100mF
5V
0.1mF
5V
Cherry Semiconductor Corporation
2000 South County Trail, East Greenwich, RI 02818
Tel: (401)885-3600 Fax: (401)885-5786
Email: info@cherry-semi.com
Web Site: www.cherry-semi.com
Rev. 3/17/99
1
A
¨
Company
CHERRY [ CHERRY SEMICONDUCTOR CORPORATION ]
