Datasheet L4964 Datasheet (SGS Thomson Microelectronics)

HIGHCURRENT SWITCHING REGULATOR

.4 AOUTPUTCURRENT

.5.1 V TO28 V OUTPUTVOLTAGERANGE

.0 TO 100 % DUTY CYCLERANGE

.PRECISE(± 3 %) ON-CHIPREFERENCE

.SWITCHINGFREQUENCY UP TO 120KHz

.VERYHIGH EFFICIENCY(UP TO 90 %)

.VERYFEW EXTERNALCOMPONENTS

.SOFTSTART

.RESETOUTPUT

.CURRENT LIMITING

.INPUT FOR REMOTE INHIBIT AND SYN-

CHRONUSPWM

.THERMALSHUTDOWN

DESCRIPTION

TheL4964isa stepdownpowerswitchingregulator
delivering4Aat a voltagevariablefrom5.1Vto28V.

Featuresof the device includeoverloadprotection,
soft start,remote inhibit,thermal protection,a reset
outputformicroprocessorsanda PWMcomparator
inputforsynchronizationinmultichipconfigurations.

TheL4964ismountedina 15-leadMultiwatt plas-
tic power package and requires very few external
components.

Efficient operation at switching frequencies up to
120kHzallowsareductionin thesizeandcostofex­ternalfilter components.

L4964

MULTIWATT15 Vertical

(PlasticPackage)

ORDERING NUMBER : L4964

MULTIWATT15 Horizontal

(PlasticPackage)

ORDERING NUMBER : L4964HT

PIN CONNECTION (top view)

April1993

Pins1, 4, 15 must not be connected. Leave open circuit.

1/13

L4964

PIN FUNCTIONS

N° Name Function

1 N.C. Must not be connected. Leave open circuit.
2 Output Regulator Output.
3 Supply Voltage Unregulated Voltage Input. An internal regulator powers the L4964’s internal logic.
4 N.C. Must not be connected. Leave open circuit.
5 Soft Start Soft Start Time Constant. A capacitor is connected between this terminal and ground

6 Inhibit Input TTL - Level Remote Inhibit. A logic high level on this input disables the L4964.
7 Sync Input Multiple L4964’s are synchronized by connecting the pin 7 inputs together and omitting

8 Ground Common Ground Terminal.
9 Frequency

Compensation

10 Feedback

Input

11 Oscillator A parallel RC network connected to this terminal determines the switching frequency.

12 Reset Input Input of the Reset Circuit. The threshold is roughly 5 V. It may be connected to the

13 Reset Delay A capacitorconnected between this terminal and ground determines the reset signal

14 Reset Output Open Collector Reset Signal Output. This output is high when the supply is safe.
15 N.C. Must not be connected. Leave open circuit.

to define the soft start time constant. This capacitor also determines the average short
circuit output current.

the oscillator RC network on all but one device.

A series RC network connected between this terminal and ground determines the
regulation loop gain characteristics.

The FeedbackTerminal of the Regulation Loop. The output is connected directly to
this terminal for 5.1 V operation ; it is connected via a divider for higher voltages.

The pin must be connected to pin 7 input when the internal oscillator is used.

beedback point or via a divider to the input.

delay time.

BLOCK DIAGRAM

2/13

CIRCUI T OPE RATION (refer t o the bl ock diagram)
TheL4964isa monolithicstepdownswitchingregu-

lator providing output voltages from 5.1 V to 28 V
anddelivering 4A.

Theregulationloopconsistsofasawtoothoscillator,
erroramplifier,comparatorandtheoutputstage.An
error signal is produced by comparing the output
voltage with a precise 5.1 V on-chip reference
(zener zap trimmed to ± 3 %). This error signal is
thencomparedwiththesawtoothsignaltogenerate
the fixed frequency pulse width modulated pulses
which drive the output stage. The gain and fre­quencystabilityoftheloop canbeajustedbyan ex­ternalRC networkconnectedto pin 9. Closing the
loopdirectlygivesanoutputvoltageof5.1V.Higher
voltagesareobtainedby insertinga voltagedivider.

Outputovercurrentsat switch on are preventedby
the soft start function.The error amplifieroutput is
initiallyclampedbytheexternalcapacitorC

andal-

ss

lowedto rise, linearly,as this capacitoris charged
bya constantcurrent source.

Outputoverloadprotectionisprovidedinthe formof
a current limiter. The load current is sensedby an
internalmetal resistor connectedto a comparator.
Whenthe load current exceedsa presetthreshold
this comparatorsets a flip flop which disables the
outputstageanddischargesthesoftstartcapacitor.

A second comparator resets the flip flop when the
voltageacross the soft start capacitorhas fallento

0.4 V. The output stage is thus re-enable and the
outputvoltagerisesundercontroofthesoftstartnet­work. If the overload condition is still present the
limiter will trigger againwhen the thersholdcurrent
isreached.The averageshortcircuit current is lim­itedto a safe value by the dead timeintroducedby
the soft start network.

The reset circuit generates an output signal when
the supply voltage exceeds a threshold pro­grammedbyan externaldivider.The resetsignal is
generatedwithadelaytimeprogrammedby an ex­ternal capacitor. When the supply falls below the
threshold the reset output goes low immediately.
Thereset output is an opencollector.

A TTL- level input is providedfor applicationssuch
as remote on/off control.This input is activated by
highlevelanddisablescircuitoperation.Afteran in­hibittheL4964restartsundercontrolofthesoftstart
network.

The thermal overloadcircuit disables circuit opera­tion when the junction temperaturereaches about
150 and has hysteresisto prevent unstable condi­tions.

L4964

Figure 1 : ResetOutputWaveforms

3/13

L4964

Figure 2 : SoftStartWaveforms

Figure 3 : CurrentLimiterWaveforms

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Value Unit

V

i

V

i–V2

V

2

V

12

V

5,V7,V9

V

10,V6,V13

V

14

I

9

I

11

I

14

P

tot

T

,T

j

Input Voltage (pin 3) 36 V
Input to Output Voltage Difference 38 V
Output DC Voltage

Output Peak Voltage at t = 0.1 µsec f = 100 kHz

–1

–7
Voltage at Pin 12 10 V
Voltage at Pins 5, 7 and 9 5.5 V
Voltage at Pins 10, 6 and 13 7 V
Voltage at Pin 14 (I14≤ 1 mA) V

i

Pin 9 Sink Current 1 mA
Pin 11 Source Current 20 mA
Pin 14 Sink Current (V14< 5 V) 50 mA
Power Dissipation at T
Junction and Storage Temperature – 40 to 150 °C

stg

≤ 90 °C20W

case

THERMAL DATA

Symbol Parameter Value Unit

4/13

R

th j-case

R

th j-amb

Thermal Resistance Junction-case Max. 3 °C/W
Thermal Resistance Junction-ambient Max. 35 °C/W

V
V

L4964

ELECTRICAL CHARACTERISTICS

(refer to the test circuits T

Symbol Parameter Test Conditions Min. Typ. Max. Unit Fig.

DYNAMIC CHARACTERISTICS (pin 6 to GND unless otherwise specified)

V

Output Voltage Range Vi= 36V, Io=1A V

o

V

Input Voltage Range Vo=V

i

∆V
∆V

V

∆V

Io

SVR Supply Voltage Ripple Rejection ∆V

∆V

∆T

f

T

DC CHARACTERISTICS

I

–I

SOFT START

I

INHIBIT

V

V

–I

–I

ERROR AMPLIFIER

V

V

I

–I

Line Regulation Vi= 10V to 30V, Vo=V

o

Load Regulation Io=1Ato2A

o

Internal Reference Voltage (Pin 10) Vi= 9V to 36V, Io= 2A 4.95 5.1 5.25 V 4

ref

Average Temperature Coefficient

ref

of Reference Voltage

∆T

Dropout Voltage between Pin 2

V

d

and Pin 3
Maximum Operating Load Current VI= 9V to 36V, Vo=V

m

I

Current Limiting Threshold (Pin 2) Vi= 9V to 36V, Vo=Vref to 28V 4.5 8 A 4

2L

I

Input Average Current Vi= 36V, Output Short-circuited 80 140 mA 4

SH

η Efficiency I

f Switching Frequency 40 50 60 kHz 4

∆f

Voltage Stability of Switching
Frequency

i

Temperature Stability of Switching

∆f

Frequency

j

Maximum Operating Switching

max

Frequency
Thermal Shutdown Junction

sd

Temperature

Quiescent Drain Current Vi= 36V, V7= 0V, S1 : B, S2 : B

3Q

Output Leakage Current Vi= 36V, V6= 3 V, V7=0V

2L

Source Current V6= 0V, V5= 3V 80 130 180 µA6b

5so

I

Sink Current V6= 3V, V5= 3V 40 70 140 µA6b

5si

Low Input Voltage Vi= 9V to 36V, V7=0V

6L

High Input Voltage 2 5.5 V 6a

6H

Input Current with Input Voltage

6L

6H

9H

9L

9si

9so

Low Level
High Level

High Level Output Voltage V10= 4.7V, I9= 100µA, S1 : A,
Low Level Output Voltage V10= 5.3V, I9= 100µA, S1 : A,

Sink Output Current V10= 5.3V, S1 : A, S2 : B 100 150 µA6c
Source Output Current V10= 4.7V, S1 : A, S2 : D 100 150 µA6c

=25oC, Vi= 25V, unless otherwise specified)

j

to 28V, Io=3A 9 36 V 4

ref

=2A 15 70 mV 4

ref,Io

= 0.5A to 3A, Vo=V

I

o

T

=0°C to 125°C, Io= 2A 0.4 mV/°C

j

ref

Io=3A

=2A

I

o

to 28V 4 A 4

ref

=3A Vo=V

o

=2V

I

V

o=Vref,Io

rms,fripple

=2A

ref

Vo= 12V

= 100Hz

Vi= 9V to 36V 0.5 % 4

Tj=0°C to 125°C1%4

Vo=V

V
V

= 1A 120 kHz –

ref,Io

=0V

6

=3V

6

S1 : B, S2 : A

S1 : B, S2 : B
Vi= 9V to 36V, V7=0V

S1 : B, S2 : B

= 0.8V

V

6

=2V

V

6

S2 : A

S2 : E

ref

28 V 4

10153050mVmV4

2

1.5

75
85

3.2

2.4

V
V

%
%

46 56 – dB 4

135 145 °C–

mA 6a

6630100

50

2mA6a

- 0.3 0.8 V 6a

µA6a

20
10

3.4 V 6c

0.6 V 6c

4

4
4

4
4

5/13

L4964

ELECTRICAL CHARACTERISTICS (continued)

(refer to the test circuits T

Symbol Parameter Test Conditions Min. Typ. Max. Unit Fig.

ERROR AMPLIFIER (continued)

I

OSCILLATOR AND PWM COMPARATOR

–I

–I

RESET

V

V

V
V

V

–I

I

13 si

Input Bias Current V10= 5.2V, S1 : B 2 20 µA6c

10

G

DC Open Loop Gain V9= 1V to 3V, S1 : A, S2 : C 40 55 dB 6c

v

Input Bias Current of

7

PWM Comparator
Oscillator Source Current V11= 2V, S1 : A, S2 : B 4 – mA 6a

11

Rising Threshold Voltage

12R

Falling Threshold Voltage 4.75 V

12F

Delay Threshold Voltage

13D

Delay Threshold Voltage

13H

Hysteresis
Output Saturation Volt. I14= 5mA, V12= 4.7V - S1, S2 : B 0.4 V 6d

14S

I

Input Bias Current V12=0VtoV

12

Delay Source Current

13 so

Delay Sink Current
Output Leakage Current Vi= 36V, V12= 5.3V, S1 : B, S2 : A 100 µA6d

I

14

=25oC, Vi= 25V, unless otherwise specified)

j

V7= 0.5V to 3.5V 10 µA6a

V

=9Vto36V,S1:B,S2:B

V

i

- 150mV

4.3 4.5 4.7 V 6d

V

= 5.3 V, S1 : A, S2 : B

12

, S1 : B, S2 : B 1 10 µA6d

ref

= 3V, S1 : A, S2 : B

V

13

= 5.3V

V

12

= 4.7V

V

12

60

8

ref

V

ref

- 100mV

ref

- 150mV

V

ref

- 50mV
V

ref

- 100mV

V6d

V6d

100 mV 6d

110 150 µA

mA

6d

Figure 4 : Dynamic Test Circuit

C7,C8 : EKR (ROE)
L1: L = 300µHat8A
R=500mΩ

Core type : MAGNETICS58930 - A2 MPP
N°turns : 43 Wire Gauge: 1 mm (18 AWG)

6/13

Figure 5 : PC.Board and Component Layoutof the Circuit of Fig. 4 (1:1scale)

L4964

7/13

L4964

Figure 6 : DC Test Circuits.
Figure 6a. Figure6b.

Figure 6c.

1 - Set V10FORV9=1V
2 - ChangeV

3-G

V

10

DV

9

=

∆V

10

to obtain V9=3V

2V

=

∆V

Figure 6d.

8/13

10

L4964

Figure 7 : SwitchingFrequencyvs. R1 (see fig. 4). Figure8 : OpenLoopFrequencyand PhaseRes-

ponse of ErrorAmplifier (see fig.6c).

Figure 9 : ReferenceVoltage(pin 10) vs.Junc-

tionTemperature(see fig. 4).

Figure10 : Power Dissipation(L4964only) vs.

Input Voltage.

Figure 11 : Efficiencyvs.OutputVoltage. Figure12 : Power DissipationDerratingCurve.

9/13

L4964

APPLICATION INFORMATION

CHOOSINGTHE INDUCTOR AND CAPACITOR
Theinput and output capacitorsof the L4964 must
havealow ESRand low inductanceat highcurrent
ripple.

Preferably,the inductorshouldbe a toroidaltypeor
wound on a Moly-Permalloy nucleus.Saturation
mustnot occuratcurrentlevelsbelow1.5 timesthe

Figure 13 : TypicalApplicationCircuit.

L 4964

currentlimiterlevel.MPPnucleihaveverysoftsatu­rationcharacteristics.

L=

(V

i−Vo)V0

Vif∆I

L

,C=

(V

i−Vo)V0

8L f2∆V

o

∆IL= Inductancecurrentripple
∆V

=Outputripplevoltage

o

C7, C8 : EKR(ROE)

SUGGESTEDINDUCTOR (L1)

Core Type

Magnetics 58930 – A2MPP 43 1.0 –
Thomson GUP 20 x 16 x 7 50 0.8 0.7
Siemens EC 35/17/10

(B6633& – G0500 – X127)
VOGT 250 µH Toroidal Coil, Part Number

5730501800

No

Turns

40 2 x 0.8 –

Wire

Gauge

(mmm)

Air

Gap

(mm)

Resistor Values for Standard Output Volt-

ages

V

12 V
15 V
18 V

0

R8 R7

4.7 kΩ

4.7 kΩ

4.7 kΩ

Figure 14 : P.C.Board and ComponentLayoutof the Circuit of Fig. 13 (1:1 scale)

6.2 kΩ

9.1 kΩ
12 kΩ

10/13

MULTIWATT15 (Vertical) PACKAGE MECHANICAL DATA

L4964

Dimensions

Min. Typ. Max. Min. Typ. Max.

Millimeters Inches

A 5 0.197

B 2.65 0.104
C 1.6 0.063
D 1 0.039
E 0.49 0.55 0.019 0.022

F 0.66 0.75 0.026 0.030
G 1.14 1.27 1.4 0.045 0.050 0.055

G1 17.57 17.78 17.91 0.692 0.700 0.705
H1 19.6 0.772
H2 20.2 0.795

L 22.1 22.6 0.870 0.890

L1 22 22.5 0.866 0.886
L2 17.65 18.1 0.695 0.713
L3 17.25 17.5 17.75 0.679 0.689 0.699
L4 10.3 10.7 10.9 0.406 0.421 0.429
L7 2.65 2.9 0.104 0.114

M 4.2 4.3 4.6 0.165 0.169 0.181

M1 4.5 5.08 5.3 0.177 0.200 0.209

S 1.9 2.6 0.075 0.102

S1 1.9 2.6 0.075 0.102

Dia. 1 3.65 3.85 0.144 0.152

MUL15V.TBL

11/13

PMMUL15V.EPS

L4964

MULTIWATT15 (Horizontal) PACKAGE MECHANICAL DATA

Dimensions

A 5 0.197
B 2.65 0.104
C 1.6 0.063
E 0.49 0.55 0.019 0.022

F 0.66 0.75 0.026 0.030
G 1.14 1.27 1.4 0.045 0.050 0.055

G1 17.57 17.78 17.91 0.692 0.700 0.705
H1 19.6 0.772
H2 20.2 0.795

L 20.57 0.810

L1 18.03 0.710
L2 2.54 0.100
L3 17.25 17.5 17.75 0.679 0.689 0.699
L4 10.3 10.7 10.9 0.406 0.421 0.429
L5 5.28 0.208
L6 2.38 0.094
L7 2.65 2.9 0.104 0.114

S 1.9 2.6 0.075 0.102

S1 1.9 2.6 0.075 0.102

Dia. 1 3.65 3.85 0.144 0.152

Min. Typ. Max. Min. Typ. Max.

Millimeters Inches

MUL15H.TBL

12/13

H1

A

C

L7

Dia. 1

S

S1

L3

L

L4

B

E

H2

PMMUL15H.EPS

L2 L1

L6

F

G1

G

L5

L4964

Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for
the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its
use. No license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specifica­tions mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information pre­viously supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or
systems withoutexpress written approval of SGS-THOMSON Microelectronics.

 1994 SGS-THOMSON Microelectronics - All Rights Reserved

MULTIWATT is a Registered Trademark of SGS-THOMSON Microelectrinics

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