Datasheet CS8221YDPR3, CS8221YDP3, CS8221YDFR8, CS8221YDF8 Datasheet (Cherry Semiconductor)

1

Features

■ Low Quiescent Current

(60µA @ 100µA load)

■ 5V, ±2% Output

■ 100mA Output Current

Capability

■ Fault Protection

+74V Peak Transient
Voltage

-15V Reverse Voltage

Short Circuit

Thermal Shutdown

Low Reverse Current
(Output to Input)

Package Options

CS8221

Micropower 5V, 100mA

Low Dropout Linear Regulator

CS8221

Description

The CS8221 is a precision 5V,
100mA micropower voltage regula­tor with very low quiescent current
(60µA typical at 100µA load). The
5V output is accurate within ±2%
and supplies 100mA of load current
with a maximum dropout voltage
of only 600mV.

The regulator is protected against
reverse battery, short circuit, over
voltage, and over temperature con­ditions. The device can withstand
74V load dump transients making it
suitable for use in automotive envi­ronments.

Block Diagram

3L D

2

PAK

Tab (Gnd)

1

1. V

IN

2. Gnd

3. V

OUT

Absolute Maximum Ratings

Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Internally Limited

Transient Peak Voltage (60V Load Dump) . . . . . . . . . . . . . . . . . . . .-15V, 74V

Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Internally Limited

ESD Susceptibility (Human Body Model) . . . . . . . . . . . . . . . . . . . . . . . . . .2kV

Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-40¡C to 150¡C

Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-55¡C to 150¡C

Lead Temperature Soldering

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

V

IN

V

OUT

NC

Sense

Gnd

Gnd

Gnd

Gnd

8L SO Narrow

(Internally Fused Leads)

A Company

¨

Rev. 12/28/98

Consult factory for TO-92.

Cherry Semiconductor Corporation

2000 South County Trail, East Greenwich, RI 02818

Tel: [phone] Fax: [phone]

Email: [e-mail]

Web Site: www.cherry-semi.com

V

IN

Current Source

(Circuit Bias)

Over

Voltage

Shutdown

V

OUT

D2PAK

1

* 8 Lead SO Narrow

Thermal

Shutdown

Bandgap

Reference

+ -

Error
Amplifier

Current Limit

Sense

Sense*

Gnd

2

Electrical Characteristics: 6V ² V

IN

² 26V, I

OUT

= 1mA, -40¡ ² TA² 125¡C, -40¡ ² TJ² 150¡C; unless otherwise specified.

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

CS8221

Package Lead Description

PACKAGE LEAD # LEAD SYMBOL FUNCTION

■ Output Stage

Output Voltage, V

OUT

9V<VIN<16V, 100µA ² I

OUT

² 100mA 4.90 5.00 5.10 V

6V ² VIN² 26V, 100µA ² I

OUT

² 100mA 4.85 5.00 5.15 V

Dropout Voltage (VIN-V

OUT

)I

OUT

= 100mA 400 600 mV

I

OUT

= 100µA 100 150 mV

Load Regulation VIN= 14V 5 50 mV

100µA ² I

OUT

² 100mA

Line Regulation 6V<V<26V 5 50 mV

I

OUT

= 1mA

Quiescent Current, (IQ)I

OUT

= 100µA, VIN= 6V 60 120 µA

I

OUT

² 50mA 4 6 mA

I

OUT

² 100mA 12 20 mA

Ripple Rejection 7V ² VIN² 17V, I

OUT

= 100mA, 60 75 dB

f = 120Hz

Current Limit 125 200 mA
Short Circuit Output Current V

OUT

= 0V 40 125 µA
Thermal Shutdown (Note 1) 150 180 ¡C
Overvoltage Shutdown V

OUT

²1V 303438 V
Reverse Current V

OUT

= 5V, VIN= 0V 100 500 µA

Note 1: This parameter is guaranteed by design, but not parametrically tested in production.

8L SO Narrow 3L

(Internally Fused Leads) D

2

PAK

11VINInput voltage.

23V

OUT

5V, ±2%, 100mA output.

3 Ð NC No connection.

4 Ð Sense Kelvin connection which allows remote sensing of the output

voltage for improved regulation. If remote sensing is not
required, connect to V

OUT

.

5,6,7,8 2 Gnd Ground.

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 should be 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, but, if the circuit operates at low tempera­tures (-25¡C to -40¡C), both the value and ESR of the
capacitor will vary considerably. The capacitor manufac­turers data sheet usually provides this information.

The value for the output capacitor C

OUT

shown in the test
and applications circuit should work for most applica­tions, however it is not necessarily the optimized solution.

To determine an acceptable value for C

OUT

for a particular
application, start with a tantalum capacitor of the recom­mended value and work towards a less expensive alterna­tive part.

Step 1: Place the completed circuit with a tantalum capac­itor of the recommended value in an environmental cham-

ber at the lowest specified operating temperature and
monitor the outputs with an oscilloscope. A decade box
connected in series with the capacitor will simulate the
higher ESR of an aluminum capacitor. Leave the decade
box outside the chamber, the small resistance added by
the longer leads is negligible.

Step 2: With the input voltage at its maximum value,
increase the load current slowly from zero to full load
while observing the output for any oscillations. If no oscil­lations are observed, the capacitor is large enough to
ensure a stable design under steady state conditions.

Step 3: Increase the ESR of the capacitor from zero using
the decade box and vary the load current until oscillations
appear. Record the values of load current and ESR that
cause the greatest oscillation. This represents the worst
case load conditions for the regulator at low temperature.

Step 4: Maintain the worst case load conditions set in step
3 and vary the input voltage until the oscillations increase.
This point represents the worst case input voltage condi­tions.

Step 5: If the capacitor is adequate, repeat steps 3 and 4
with the next smaller valued capacitor. A smaller capaci-

Output Stage Protection

The output stage is protected against overvoltage, short
circuit and thermal runaway conditions (Figure 1).

If the input voltage rises above 34V (typ), the output shuts
down. This response protects the internal circuitry and
enables the IC to survive unexpected voltage transients.

Should the junction temperature of the power device
exceed 180ûC (typ) the power transistor is turned off.
Thermal shutdown is an effective means to prevent die
overheating since the power transistor is the principle heat
source in the IC.

3

CS8221

Application Notes

Application & Test Diagram

Voltage Reference and Output Circuitry

Stability Considerations

Circuit Description

Figure 1. Typical Circuit Waveforms for Output Stage Protection.

* 8 Lead SO Narrow only
**C1 is required if regulator is distant from power source filter.
***C2 is required for stability.

> 30V

V

IN

V

OUT

I

OUT

Load

Dump

Short

Circuit

Thermal

Shutdown

V

IN

C1**

0.1mF

CS8221

V

OUT

C2***
10mF

Sense*

Gnd

4

tor will usually cost less and occupy less board space. If
the output oscillates within the range of expected operat­ing conditions, repeat steps 3 and 4 with the next larger
standard capacitor value.

Step 6: Test the load transient response by switching in
various loads at several frequencies to simulate its real
working environment. Vary the ESR to reduce ringing.

Step 7: Remove the unit from the environmental chamber
and heat the IC with a heat gun. Vary the load current as
instructed in step 5 to test for any oscillations.

Once the minimum capacitor value with the maximum
ESR is found, a safety factor should be added to allow for
the tolerance of the capacitor and any variations in regula­tor performance. Most good quality aluminum electrolytic
capacitors have a tolerance of ±20% so the minimum value
found should be increased by at least 50% to allow for this
tolerance plus the variation which will occur at low tem­peratures. The ESR of the capacitor should be less than
50% of the maximum allowable ESR found in step 3
above.

The maximum power dissipation for a single output regu­lator (Figure 2) is:

P

D(max)

= {V

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

(1)

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 applica-

tion, and
IQis the quiescent current the regulator consumes at

I

OUT(max)

.

Once the value of P

D(max)

is known, the maximum permis-

sible value of R

QJA

can be calculated:

R

QJA

= (2)

Figure 2. Single output regulator with key performance parameters
labeled.

The value of R

QJA

can then be compared with those in
the package section of the data sheet. Those packages
with R

QJA

's less than the calculated value in equation 2

will keep the die temperature below 150¡C.
In some cases, none of the packages will be sufficient to

dissipate the heat generated by the IC, and an external
heatsink will be required.

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 will have a thermal resistance. Like
series electrical resistances, these resistances are summed
to determine the value of R

QJA

:

R

QJA

= R

QJC

+ R

QCS

+ R

QSA

(3)

where:

R

QJC

= the junctionÐtoÐcase thermal resistance,

R

QCS

= the caseÐtoÐheatsink thermal resistance, and

R

QSA

= the heatsinkÐtoÐambient thermal resistance.

R

QJC

appears in the package section of the data sheet. Like

R

QJA

, it too is a function of package type. R

QCS

and R

QSA

are functions of the package type, heatsink and the inter­face between them. These values appear in heat sink data
sheets of heat sink manufacturers.

Heat Sinks

150¡C - T

A

P

D

Calculating Power Dissipation

in a Single Output Linear Regulator

Application Notes: continued

CS8221

I

V

IN

IN

I

OUT

CS8221

I

Q

V

OUT

5

Thermal Data 8 Lead 3 Lead

SO Narrow D

2

PAK

(internally fused leads)

R

QJC

typ 25 4.2 ûC/W

R

QJA

typ 110 10-50* ûC/W

*Depending on thermal properties of substrate. R

QJA

= R

QJC

+ R

QCA

D

Lead Count Metric English

Max Min Max Min

8L SO Narrow 5.00 4.80 .197 .189

(internally fused leads)

Package Specification

PACKAGE DIMENSIONS IN mm (INCHES)

PACKAGE THERMAL DATA

CS8221

Surface Mount Narrow Body (D); 150 mil wide

1.27 (.050) BSC

0.51 (.020)

0.33 (.013)

6.20 (.244)

5.80 (.228)

4.00 (.157)

3.80 (.150)

1.57 (.062)

1.37 (.054)

D

0.25 (0.10)

0.10 (.004)

1.75 (.069) MAX

1.27 (.050)

0.40 (.016)

REF: JEDEC MS-012

0.25 (.010)

0.19 (.008)

6

CS8221

Part Number Description

CS8221YDF8 8L SO Narrow (internally fused leads)
CS8221YDFR8 8L SO Narrow (internally fused leads)

(tape & reel)

CS8221YDP3 3L D2PAK
CS8221YDPR3 3L D

2

PAK (tape & reel)

Ordering Information

Rev. 12/28/98

Package Specification

© 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.

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)