CS5203-1GT3 ON Semiconductor, CS5203-1GT3 Datasheet - Page 5

• Manufacturer Part Number: CS5203-1GT3
• Description: IC REG LINEAR ADJ OUT 3A TO220AB
• Manufacturer: ON Semiconductor

Specifications of CS5203-1GT3

• Regulator Topology: Positive Adjustable
• Voltage - Output: 1.25 ~ 5.5 V
• Voltage - Input: Up to 7V
• Voltage - Dropout (typical): 1.15V @ 3A
• Number Of Regulators: 1
• Current - Output: 3A
• Current - Limit (min): 3.1A
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Through Hole
• Package / Case: TO-220-3 (Straight Leads)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: CS5203-1GT3OS

at currents up to 3.0 A. The regulator is protected against
overcurrent conditions and includes thermal shutdown.
transistor and requires an output capacitor for stability. A
detailed procedure for selecting this capacitor is included in
the Stability Considerations section.
Adjustable Operation
5.5 V. An external resistor divider sets the output voltage as
shown in Figure 12. The regulator maintains a fixed 1.25V
(typical) reference between the output pin and the adjust pin.
to flow to ground. This current creates a voltage across R2
that adds to the 1.25 V across R1 and sets the overall output
voltage. The adjust pin current (typically 50 mA) also flows
through R2 and adds a small error that should be taken into
account if precise adjustment of V
pin current.
2.0 mA. R1 and R2 should be the same type, e.g. metal film
for best tracking over temperature. While not required, a
bypass capacitor from the adjust pin to ground will improve
ripple rejection and transient response. A 0.1 mF tantalum
capacitor is recommended for “first cut” design. Type and
value may be varied to obtain optimum performance vs.
price.
specification of 7.0 V for the voltage difference between V
and V
in excess of 7.0 V. The main considerations in such a design
are power−up and short circuit capability.
The CS5203−1 linear regulator provides adjustable voltages
The CS5203−1 has a composite PNP−NPN output
The CS5203−1 has an output voltage range of 1.25 V to
A resistor divider network R1 and R2 causes a fixed current
The output voltage is set according to the formula:
The term I
R1 is chosen so that the minimum load current is at least
The CS5201−1 linear regulator has an absolute maximum
V
IN
OUT
V OUT + V REF
. However, the IC may be used to regulate voltages
Figure 12. Resistor Divider Scheme
Adj
C
1
× R2 represents the error added by the adjust
V
IN
CS5203−1
Adj
V
C
OUT
R1 ) R2
Adj
R1
I
Adj
V
OUT
REF
) I Adj
is necessary.
R
R
1
2
APPLICATIONS INFORMATION
R2
C
V
2
OUT
http://onsemi.com
IN
5
is fairly slow, typically on the order of several tens of
milliseconds, while the regulator responds in less than one
microsecond. In this case, the linear regulator begins
charging the load as soon as the V
large enough that the pass transistor conducts current. The
load at this point is essentially at ground, and the supply
voltage is on the order of several hundred millivolts, with the
result that the pass transistor is in dropout. As the supply to
V
current is passed to the load until V
which the IC is in regulation. Further increase in the supply
voltage brings the pass transistor out of dropout. The result
is that the output voltage follows the power supply ramp−up,
staying in dropout until the regulation point is reached. In
this manner, any output voltage may be regulated. There is
no theoretical limit to the regulated voltage as long as the
V
circuit condition is very real for this type of design. Short
circuit conditions will result in the immediate operation of
the pass transistor outside of its safe operating area.
Over−voltage stresses will then cause destruction of the pass
transistor before overcurrent or thermal shutdown circuitry
can become active. Additional circuitry may be required to
clamp the V
fail−safe operation is required. One possible clamp circuit is
illustrated in Figure 13; however, the design of clamp
circuitry must be done on an application by application
basis. Care must be taken to ensure the clamp actually
protects the design. Components used in the clamp design
must be able to withstand the short circuit condition
indefinitely while protecting the IC.
IN
IN
In most applications, ramp−up of the power supply to V
However, the possibility of destroying the IC in a short
increases, the pass transistor will remain in dropout, and
to V
EXTERNAL SUPPLY
Figure 13. Short Circuit Protection Circuit for
OUT
IN
differential of 7.0 V is not exceeded.
V
to V
IN
High Voltage Application.
V
Adj
OUT
V
OUT
differential to less than 7.0 V if
V
OUT
IN
OUT
to V
reaches the point at
OUT
differential is
IN