Datasheet CS5203-3GDPR3, CS5203-3GDP3 Datasheet (Cherry Semiconductor)

1

Features

■ Output Current to 3A

■ Output Accuracy to ±1.5%

Over Temperature

■ Dropout Voltage (typical)

1.15V @ 3A

■ Fast Transient Response

■

Fault Protection

Current Limit
Thermal Shutdown

Package Options

CS5203-3

3A, 3.3V Fixed Linear Regulator

CS5203-3

Application Diagram

CS5203 -3

1 Gnd
2V

OUT (Tab)

3V

IN

Description

3L D2PAK

Tab (V

OUT

)

1

Consult factory for other package
options.

The CS5203-3 linear regulator
provides a 3.3V reference at 3A
with an output voltage accuracy
of ±1.5%.

This regulator is intended for
use as a post regulator and
microprocessor supply. The fast
loop response and low dropout
voltage make this regulator
ideal for applications where low
voltage operation and good
transient response are impor­tant.

The circuit is designed to pro­vide 3A of output current with
dropout voltages of less than

1.15V. The maximum quiescent
current is only 10mA at full
load. Device protection includes
overcurrent and thermal shut­down.

The CS5203-3 is pin compatible
with the LT1085 family of linear
regulators.

The regulator is available in a
surface mount D

2

package.

Rev. 6/3/98

Cherry Semiconductor Corporation

2000 South County Trail, East Greenwich, RI 02818

Tel: [phone] Fax: [phone]

Email: [e-mail]

Web Site: www.cherry-semi.com

A Company

¨

V

IN

5V

V

OUT

CS5203-3

3.3V

@ 3A

100mF

5V

GND

10mF
5V

D2PAK

1 Gnd Ground connection.

2V

OUT

Regulated output voltage (case).

3V

IN

Input voltage.

CS5203-3

Package Pin Description

PACKAGE PIN # PIN SYMBOL FUNCTION

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

Electrical Characteristics: C

IN

= 10µF, C

OUT

= 22µF Tantalum, V

OUT

+ V

DROPOUT

< VIN< 7V, 0¡C ² TA ² 70¡C, TJ² +150¡C,

unless otherwise specified, I

full load

= 3A.

2

Absolute Maximum Ratings

Supply Voltage, V

IN

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7V

Operating Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-40¡C to 70¡C

Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .150¡C

Storage Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-60¡C to 150¡C

Lead Temperature Soldering

Reflow (SMD styles only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60 sec. max above 183¡C, 230¡C peak

ESD Damage Threshold (Human Body Model) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2kV

■ Fixed Output Voltage

Output Voltage VINÐV

OUT

=1.5V; 3.250 3.300 3.350 V

(Notes 1 and 2) 0²I

OUT

²3A (-1.5%) (+1.5%)

Line Regulation 2V²VINÐV

OUT

²3.7V; I

OUT

=10mA 0.02 0.20 %

Load Regulation VINÐV

OUT

=2V; 10mA²I

OUT

²3A 0.04 0.4 %

(Notes 1 and 2)

Dropout Voltage (Note 3) I

OUT

=3A 1.15 1.4 V

Current Limit VINÐV

OUT

=3V 3.1 4.6 A

Quiescent Current I

OUT

=10mA 6.0 10.0 mA
Thermal Regulation (Note 4) 30ms pulse; TA=25¡C 0.002 0.020 %/W
Ripple Rejection (Note 4) f=120Hz; I

OUT

=3A; VINÐV

OUT

=3V; 80 dB

V

RIPPLE

=1V

PP

Thermal Shutdown (Note 5) 150 180 210 ¡C
Thermal Shutdown Hysteresis 25 ¡C

(Note 5)

Note 1: Load regulation and output voltage are measured at a constant junction temperature by low duty cycle pulse testing. Changes in output

voltage due to temperature changes must be taken into account separately.
Note 2: Specifications apply for an external Kelvin sense connection at a point on the output pin 1/4Ó from the bottom of the package.
Note 3: Dropout voltage is a measurement of the minimum input/output differential at full load.
Note 4: Guaranteed by design, not tested in production.
Note 5: Thermal shutdown is 100% functionally tested in production.

CS5203-3

3

Typical Performance Characteristics

Dropout Voltage vs. Output Current

Output Voltage Deviation vs Temperature

Load Regulation vs. Output Current

Block Diagram

Ripple Rejection vs Frequency

V

OUT

V

IN

Output

Current

Limit

Thermal

Shutdown

+

-

Error

Amplifier

Bandgap

Reference

Gnd

1.20

1.15

1.10

1.05

1.00

0.95

0.90

Dropout Voltage (V)

0.85

0.80

0.75

0.00 3.00

T

CASE

T

CASE

= 25°C

0.16

0.12

0.08

0.04

Output Voltage Deviation (%)

0.000

0 1.5 3

= 0°C

Output Current (A)

T

= 25°C

CASE

Output Current (A)

+0.3

+0.2

+0.1

T

CASE

= 125°C

T

CASE

2.702.402.101.801.501.200.900.600.30

= 125°C

T

CASE

= 0°C

-0.1

Reference Voltage Deviation (%)

-0.2

-0.3

Ripple Rejection (dB)

0

030

85

75

65

55

T

= 25°C

45

35

25

15

10

CASE

= 1A

I

OUT

Ð V

(V
V

RIPPLE

1

) = 3V

IN

OUT

= 1.0V

2

10

60 90 120

TJ (°C)

PP

3

10

Frequency (Hz)

4

10

5

10

6

10

4

CS5203-3

Applications Information

The CS5203-3 linear regulator provides a fixed 3.3V out­put voltage at currents up to 3A. The regulator is protect­ed against overcurrent conditions and includes thermal
shutdown.

The CS5203-3 has a composite PNP-NPN output transistor
and requires an output capacitor for stability.

The output or compensation capacitor helps determine
three main characteristics of a linear regulator: start-up
delay, load transient response and loop stability.

The capacitor value and type are based on cost, availabili­ty, size and temperature constraints. A tantalum or alu­minum electrolytic capacitor is best, since a film or ceramic
capacitor with almost zero ESR can cause instability. The
aluminum electrolytic capacitor is the least expensive solu­tion. However, when the circuit operates at low tempera­tures, both the value and ESR of the capacitor will vary
considerably. The capacitor manufacturersÕ data sheet pro­vides this information.

A 22µF tantalum capacitor will work for most applications,
but with high current regulators such as the CS5203-3 the
transient response and stability improve with higher val­ues of capacitance. The majority of applications for this
regulator involve large changes in load current so the out­put capacitor must supply the instantaneous load current.
The ESR of the output capacitor causes an immediate drop
in output voltage given by:

ÆV = ÆI ´ ESR

For microprocessor applications it is customary to use an
output capacitor network consisting of several tantalum
and ceramic capacitors in parallel. This reduces the overall
ESR and reduces the instantaneous output voltage drop
under load transient conditions. The output capacitor net­work should be as close as possible to the load for the best
results.

When large external capacitors are used with a linear regu­lator it is sometimes necessary to add protection diodes. If
the input voltage of the regulator gets shorted, the output
capacitor will discharge into the output of the regulator.
The discharge current depends on the value of the capaci­tor, the output voltage and the rate at which V

IN

drops. In
the CS5203-3 linear regulator, the discharge path is
through a large junction and protection diodes are not
usually needed. If the regulator is used with large values
of output capacitance and the input voltage is instanta­neously shorted to ground, damage can occur. In this case,
a diode connected as shown in Figure 1 is recommended.

Figure 1. Protection diode scheme for large output capacitors.

Since the CS5203-3 is a three terminal regulator, it is not
possible to provide true remote load sensing. Load regula­tion is limited by the resistance of the conductors connect­ing the regulator to the load. For best results, the regulator
should be connected as shown in figure 2.

Output Voltage Sensing

Protection Diodes

Stability Considerations

Transient Response

Typical Performance Characteristics: continued

Short Circuit Current vs. VIN- V

OUT

6.00

DV
(mV)

I(A)

OUT

+200

-200

0

3

2

1

0

0

5

Time (ms)

V

= 5V

IN

V

= 3.3V

OUT

C

= 100mF

IN

= 10mF Tantalum

C

OUT

5.00

4.00

(A)

SC

3.00

I

2.00

1.00

0.00

10

1.0 1.50 2.0 2.5 3.0 3.5

V

(V)

IN-VOUT

IN4002 (optional)

V

IN

C

1

V

IN

CS5203-3

GND

V

OUT

V

OUT

C

2

5

Applications Information: continued

CS5203-3

Figure 2. Conductor parasitic resistance effects can be minimized with
the above grounding scheme for fixed output regulators.

The CS5203-3 linear regulator includes thermal shutdown
and current limit circuitry to protect the device. High
power regulators such as these usually operate at high
junction temperatures so it is important to calculate the
power dissipation and junction temperatures accurately to
ensure that an adequate heat sink is used.

The case is connected to V

OUT

on the CS5203-3, and electri­cal isolation may be required for some applications.
Thermal compound should always be used with high cur­rent regulators such as these.

The thermal characteristics of an IC depend on the follow­ing four factors:

1. Maximum Ambient Temperature T

A

(¡C)

2. Power dissipation P

D

(Watts)

3. Maximum junction temperature T

J

(¡C)

4. Thermal resistance junction to ambient R

QJA

(C/W)

These four are related by the equation

TJ= TA+ PD´ R

QJA

(1)

The maximum ambient temperature and the power dissi­pation are determined by the design while the maximum
junction temperature and the thermal resistance depend
on the manufacturer and the package type.

The maximum power dissipation for a regulator is:

P

D(max)

={V

IN(max)ÐVOUT(min)}IOUT(max)+VIN(max)IQ

(2)

where
V

IN(max)

is the maximum input voltage,

V

OUT(min)

is the minimum output voltage,

I

OUT(max)

is the maximum output current, for the application

I

Q

is the maximum quiescent current at I

OUT

(max).

A heat sink effectively increases the surface area of the
package to improve the flow of heat away from the IC and
into the surrounding air.

Each material in the heat flow path between the IC and the
outside environment has a thermal resistance. Like series
electrical resistances, these resistances are summed to
determine R

QJA

, the total thermal resistance between the

junction and the surrounding air.

1. Thermal Resistance of the junction to case, R

QJC

(¡C/W)

2. Thermal Resistance of the case to Heat Sink, R

QCS

(¡C/W)

3. Thermal Resistance of the Heat Sink to the ambient air,
R

QSA

(¡C/W)

These are connected by the equation:

R

QJA

= R

QJC

+ R

QCS

+ R

QSA

(3)

The value for R

QJA

is calculated using equation (3) and the

result can be substituted in equation (1).
The value for R

QJC

is 3.5ûC/W. For a high current regula­tor such as the CS5203-3 the majority of the heat is generat­ed in the power transistor section. The value for R

QSA

depends on the heat sink type, while R

QCS

depends on fac­tors such as package type, heat sink interface (is an insula­tor and thermal grease used?), and the contact area
between the heat sink and the package. Once these calcula­tions are complete, the maximum permissible value of
R

QJA

can be calculated and the proper heat sink selected.
For further discussion on heat sink selection, see applica­tion note ÒThermal Management for Linear Regulators.Ó

Calculating Power Dissipation and Heat Sink Requirements

conductor
parasitic resistance

R

V

IN

V

IN

CS5203-3

GND

V

OUT

C

R

LOAD

6

© 1999 Cherry Semiconductor Corporation

Cherry Semiconductor Corporation reserves the
right to make changes to the specifications without
notice. Please contact Cherry Semiconductor
Corporation for the latest available information.

Part Number Type Description

CS5203-3GDP3 3A, 3.3V output 3 L D2PAK
CS5203-3GDPR3 3A, 3.3V output 3 L D

2

PAK (tape & reel)

CS5203-3

Ordering Information

Rev. 6/3/98

Package Specification

PACKAGE DIMENSIONS IN mm(INCHES)

3L

Thermal Data D2PAK

R

QJC

typ 3.5 ûC/W

R

QJA

typ 10 - 50* ûC/W

*Depending on thermal properties of substrate. R

QJA

= R

QJC

+ R

QCA

PACKAGE THERMAL DATA

3 Lead D2PAK (DP)

2.54 (.100) REF

10.31 (.406)

10.05 (.396)

8.53 (.336)

8.28 (.326)

0.91 (.036)

0.66 (.026)

1.40 (.055)

1.14 (.045)

4.57 (.180)

4.31 (.170)

1.68 (.066)

1.40 (.055)

2.74(.108)

2.49(.098)

1.40 (.055)

1.14 (.045)

0.10 (.004)

0.00 (.000)

.254 (.010) REF

15.75 (.620)

14.73 (.580)

2.79 (.110)

2.29 (.090)