STMicroelectronics MC34063EC Dc-dc converter control circuit Datasheet

MC34063A
MC34063E
®
DC-DC CONVERTER CONTROL CIRCUITS
■
■
■
■
■
■
OUTPUT SWITCH CURRENT IN EXCESS OF
1.5A
2% REFERENCE ACCURACY
LOW QUIESCENT CURRENT: 2.5mA (TYP.)
OPERATING FROM 3V TO 40V
FREQUENCY OPERATION TO 100KHz
ACTIVE CURRENT LIMITING
DESCRIPTION
The MC34063A/E series is a monolithic control
circuit delivering the main functions for DC-DC
voltage converting.
The device contains an internal temperature
compensated reference, comparator, duty cycle
controlled oscillator with an active current limit
circuit, driver and high current output switch.
Output voltage is adjustable through two external
resistors with a 2% reference accuracy.
Employing a minimum number of external
components the MC34063A/E devices series is
designed
for
Step-Down,
Step-Up
and
Voltage-Inverting applications.
DIP-8
SO-8
BLOCK DIAGRAM
March 2001
1/15
MC34063A/E
ABSOLUTE MAXIMUM RATINGS
Symbol
V CC
Parameter
Value
Unit
50
V
Power Supply Voltage
-0.3 to 40
V
V SWC
Switch Collector Voltage
40
V
V SWE
V ir
Comparator Input Voltage Range
Switch Emitter Voltage (VSWC = 40V)
40
V
V CE
Switch Collector toEmitter Voltage
40
V
Vdc
Driver Collector Voltage
40
V
I dc
Driver Collector Current
100
mA
I SW
Switch Current
P tot
Power Dissipation at Tamb = 25 oC (for Plastic Package)
(for SOIC Package)
1.5
A
1.25
0.625
W
T op
Operating Ambient Temperature Range (for AC and EC SERIES)
(for AB SERIES)
(for EB SERIES)
0 to 70
- 40 to 85
- 40 to 125
o
T st g
Storage Temperature Range
- 40 to 150
o
C
C
o
C
o
C
Absolute Maximum Rating are those values beyond which damage to the device may occur.
Functional operation under these condition is not implied.
THERMAL DATA
Symbol
Parameter
DIP-8
R thj-amb Thermal Resistance Junction-ambient (*)
Max
SO-8
100
160
Unit
o
C/W
(*) This value depends from thermal design of PCB on which the device is mounted.
CONNECTION DIAGRAM (top view)
PIN CONNECTIONS
Pin No
Symbol
Name and Function
1
SWC
Switch Collector
2
SWE
Switch Emitter
3
TC
4
GND
5
CII
Comparator Inverting Input
Voltage Supply
6
V CC
7
I pk
8
DRC
Timing Capacitor
Ground
Ipk Sense
Voltage Driver Collector
ORDERING NUMBERS
Type
DIP-8
SO-8
SO-8 (tape & reel)
MC34063AB (*)
MC34063ABN
MC34063ABD
MC34063ABD-TR
MC34063AC (*)
MC34063ACN
MC34063ACD
MC34063ACD-TR
MC34063EB
MC34063EBN
MC34063EBD
MC34063EBD-TR
MC34063EC
MC34063ECN
MC34063ECD
MC34063ECD-TR
(*) The "A" version is not recommended for new designs.
2/15
MC34063A/E
ELECTRICAL CHARACTERISTICS (Refer to the test circuits, VCC = 5V, Ta = TLOW to THIGH, unless
otherwise specified, see note 2)
OSCILLATOR
Symbol
f OSC
I chg
I dischg
Parameter
Frequency
Test Conditions
Vpin5 = 0 V
CT = 1 nF
o
Ta = 25 C
o
Min.
Typ.
Max.
Unit
24
33
42
KHz
Charge Currernt
VCC = 5 to 40 V
Ta = 25 C
24
33
42
µA
Discharge Current
VCC = 5 to 40 V
Ta = 25 oC
140
200
260
µA
o
Idischg /I chg Discharge to Charge
Current Ratio
Pin 7 = VCC
Ta = 25 C
5.2
6.2
7.5
V ipk(sense) Current Limit Sense Voltage
Ichg = Idischg
Ta = 25 oC
250
300
350
mV
Test Conditions
Min.
Typ.
Max.
Unit
1
1.3
V
0.45
0.7
V
100
µA
OUTPUT SWITCH
Symbol
Parameter
V CE(sat)
Saturation Voltage,
Darlington Connection
ISW = 1 A
V CE(sat)
Saturation Voltage
ISW = 1 A Rpin8 = 82 Ω to VCC,
Forced β ~ 20
DC Current Gain
ISW = 1 A
Collector Off-State Current
VCE = 40 V
h FE
I C(off)
Pins 1, 8 connected
VCE = 5 V
Ta = 25 oC
50
120
0.01
COMPARATOR
Symbol
V th
Reg line
II B
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
1.225
1.21
1.25
1.275
1.29
V
V
VCC = 3 to 40 V
1
5
mV
VIN = 0 V
-5
-400
nA
Typ.
Max.
Unit
VCC = 5 to 40 V
CT = 1 nF
Pin 7 = VCC Vpin5 > Vth Pin 2 = GND
Remaining pins open
for MC34063A
for MC34063E
2.5
1.5
4
4
mA
mA
Ta = 25 oC CT = 1 µF
for MC34063A
for MC34063E
2.1
1.5
Threshold Voltage
Ta = 25 oC
Ta = TLOW to THIGH
Threshold Voltage Line
Regulation
Input Bias Current
TOTAL DEVICE
Symbol
I CC
Parameter
Supply Current
V START-UP Start-up Voltage (note 4)
Test Conditions
Min.
Pin 5 = 0 V
V
V
NOTES:
1) Maximum package power dissipation limit must be observed.
2) TLOW = 0 oC, THIGH = 70 oC (AC and EC series); TLOW = -40 oC, THIGH = 85 oC (AB series); TLOW = -40 oC, THIGH = 125 oC (EB series).
3) If Darlington configuration is not used, care must be taken to avoid deep saturation of output switch. The resulting switch-off time may be
adversely affected. In a Darlington configuration the following output driver condition is suggested:
Forced β of output current switch = ICOUTPUT/(ICDRIVER - 1mA*) ≥ 10
* Current less due to a built in 1KΩ antileakage resistor.
4) Start-up Voltage is the minimum Power Supply Voltage at which the internal oscillator begins to work.
3/15
MC34063A/E
TYPICAL ELECTRICAL CHARACTERISTICS
Emitter Follower Configuration Output Saturation
Voltage vs Emitter Current
Output Switch ON-OFF Time vs Oscillator
Timing Capacitor
Common Emitter Configuration Output Switch
Saturation Voltage vs Collector Current
Darlington Configuration Collector Emitter
Saturation Voltage (VCE(sat)) vs Temperature
Power Collector Emitter Saturation Voltage
(VCE(sat)) vs Temperature
Current Limit Sense Voltage Voltage (Vipk) vs
Temperature
4/15
MC34063A/E
TYPICAL ELECTRICAL CHARACTERISTICS (Continued)
Reference Voltage vs Temperature
Bias Current vs Temperature
Supply Current vs Temperature
Supply Current vs Input Voltage
5/15
MC34063A/E
TYPICAL APPLICATION CIRCUIT
Step-Up Converter
Printed Demoboard
Symbol
Pin
Vout
1
GND
2
GND
3
Vin
4
Test Condition (VOUT = 28V)
Test
Conditions
Value (Typ.)
Unit
30
mV
10
mV
IO = 175 mA
300
mV
IO = 175 mA
89
%
Line Regulation
VIN = 8 to 16V,
Load Regulation
VIN = 12V,
IO = 75 to 175 mA
Output Ripple
VIN = 12V,
Efficency
VIN = 12V,
6/15
IO = 175 mA
MC34063A/E
Step-Down Converter
Printed Demoboard
Symbol
Pin
Vout
1
GND
2
GND
3
Vin
4
Test Condition (VOUT = 5V)
Test
Value (Typ.)
Unit
IO = 500 mA
Conditions
5
mV
VIN = 25V,
IO = 50 to 500 mA
30
mV
Output Ripple
VIN = 25V,
IO = 500 mA
100
mV
Efficency
VIN = 25V,
IO = 500 mA
80
%
ISC
VIN = 25V,
RLOAD = 0.1Ω
1.2
A
Line Regulation
VIN = 15 to 25V,
Load Regulation
7/15
MC34063A/E
Voltage Inverting Converter
Printed Demoboard
Symbol
Pin
Vout
1
GND
2
GND
3
Vin
4
Test Condition (VOUT = -12V)
Test
Value (Typ.)
Unit
IO = 100 mA
Conditions
15
mV
VIN = 5V,
IO = 10 to 100 mA
20
mV
Output Ripple
VIN = 5V,
IO = 100 mA
230
mV
Efficency
VIN = 5V,
IO = 100 mA
58
%
ISC
VIN = 5V,
RlLOAD = 0.1Ω
0.9
A
Line Regulation
VIN = 4.5 to 6V,
Load Regulation
8/15
MC34063A/E
Calculation
Parameter
ton/toff
Step-Up
(Discontinuos mode)
Step-Down
(Continuos mode)
Voltage Inverting
(Discontinuos mode)
Vout + VF − Vin(min)
Vin(min) − Vsat
Vin(min) − Vsat − Vout
Vout + VF
| Vout | + VF
Vin − Vsat
(ton + toff)max
CT
IPK(switch)
RSC
CO
L(min)
1/f min
1/fmin
1/f min
4.5x10-5 t on
4.5x10 -5 ton
4.5x10 -5 t on
2I out(max) [(t on /t off )+1]
2I out(max)
2I out(max) [(t on /t off )+1]
0.3/I PK(switch)
0.3/I PK(switch)
0.3/IPK(switch)
≅
Iout ton
Vripple (p−p)
Vin(min) − Vsat
ton (max)
IPK (switch)
IPK (switch) (ton + toff )
8Vripple (p−p)
Vin(min) − Vsat − Vout
ton (max)
IPK (switch)
≅
Iout ton
Vripple (p−p)
Vin(min) − Vsat
ton (max )
IPK (switch)
NOTES:
Vsat = Saturation voltage of the output switch
VF = Foward voltage drop of the output rectifier
THE FOLLOWING POWER SUPPLY CHARACTERISTICS MUST BE CHOSEN:
Vin = Nominal input voltage
Vout = Desired output voltage, |Vout| = 1.25(1+R2/R1)
Iout = Desired output current
fmin = Minimum desired output switching frequency at the selected values of Vin and Io
Vripple = Desired peak to peak output ripple voltage. In practice, the calculaed capacitor value will and to be increased due to its equivalent
series resistance and board layout. The ripple voltage should be kept to a low value since it will directly affect the line and load regulation.
Step-up With External NPN Switch
9/15
MC34063A/E
Step-down With External NPN Switch
Step-down With External PNP Switch
10/15
MC34063A/E
Voltage Inverting With External NPN Switch
Voltage Inverting With External PNP Saturated Switch
11/15
MC34063A/E
Dual Output Voltage
Higher Output Power, Higher Input Voltage
12/15
MC34063A/E
Plastic DIP-8 MECHANICAL DATA
mm
DIM.
MIN.
A
TYP.
inch
MAX.
MIN.
3.3
TYP.
MAX.
0.130
a1
0.7
B
1.39
1.65
0.055
0.065
B1
0.91
1.04
0.036
0.041
b
b1
0.028
0.5
0.38
0.020
0.5
D
0.015
0.020
9.8
0.386
E
8.8
0.346
e
2.54
0.100
e3
7.62
0.300
e4
7.62
0.300
F
7.1
0.280
I
4.8
0.189
L
Z
3.3
0.44
0.130
1.6
0.017
0.063
P001F
13/15
MC34063A/E
SO-8 MECHANICAL DATA
mm
DIM.
MIN.
TYP.
A
a1
inch
MAX.
MIN.
TYP.
1.75
0.1
0.068
0.25
a2
MAX.
0.003
0.009
1.65
0.064
a3
0.65
0.85
0.025
0.033
b
0.35
0.48
0.013
0.018
b1
0.19
0.25
0.007
0.010
C
0.25
0.5
0.010
0.019
5.0
0.188
0.196
6.2
0.228
c1
45 (typ.)
D
4.8
E
5.8
0.244
e
1.27
0.050
e3
3.81
0.150
F
3.8
4.0
0.14
0.157
L
0.4
1.27
0.015
0.050
M
S
0.6
0.023
8 (max.)
0016023
14/15
MC34063A/E
Information furnished is believed to be accurate and reliable. However, STMicroelectronics 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 STMicroelectronics. Specification mentioned in this publication are
subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products
are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.
The ST logo is a registered trademark of STMicroelectronics
© 2001 STMicroelectronics – Printed in Italy – All Rights Reserved
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15/15
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