Seme LAB IP35063 Dc-dc converter control circuit Datasheet

IP35063
IP33063
IP34063
DC–DC CONVERTER
CONTROL CIRCUIT
TOP VIEW
SW ITCH
COLLECTOR
1
8
D RIVER
C OLLEC TO R
SW ITCH
EMITTER
2
7
Ipk SENSE
TIM ING
C APACITOR
3
6
VC C
GND
4
5
C OMP AR ATOR
INVER TIN G
INPUT
FEATURES
J Package – 8 Pin Ceramic DIP
N Package – 8 Pin Plastic DIP
D-8 Package – 8 Pin Plastic (150) SOIC
•
•
•
•
•
•
•
Operation from 2.5 to 40V input
Low Standby Current
Current Limiting
Output switch current of 1.5A
Output voltage adjustable from 1.25 to 40V
Operating frequency from 100Hz to 100kHz
Direct replacement for MC34063/MC34063A
series
Order Information
Part
Number
IP35063
IP33063
IP34063
J–Pack
8 Pin
✔
✔
✔
N–Pack
8 Pin
D–8
8 Pin
✔
✔
✔
✔
Temp.
Range
-55 to +125°C
-40 to +85°C
0 to +70°C
Note:
To order, add the package identifier to the part
number.
eg.
IP35063D–8
ABSOLUTE MAXIMUM RATINGS
+40V
Power Supply Voltage
–0.3V to +40V
Comparator Input Voltage Range
Switch Collector Voltage
40V
Switch Emitter Voltage
40V
Switch Collector to Emitter Voltage
40V
Driver Collector Voltage
40V
Switch Current
1.5A
Power Dissipation @ Tamb = 25°C
Ceramic Packages
Plastic Packages
10mW/°C
Derate above 25°C
Operating Junction Temperature
Ceramic Packages
Plastic Packages
Operating Ambient Temperature Range See Table Above
Storage Temperature Range
Semelab plc.
1.25W
1W
Telephone (01455) 556565. Telex: 341927. Fax (01455) 552612.
150°C
125°C
See Table Above
–65 to 150°C
Prelim. 2/95
IP35063
IP33063
IP34063
DESCRIPTION
Driver
Collector
The IP34063 series of control circuits contains all the
functions required to implement DC–DC converters.
Included are internal voltage reference, comparator,
controlled duty cycle oscillator with current limit circuit,
driver, and high current output switch. This series was
specifically designed to be incorporated in Step-Down
(Buck) and Step-Up (Boost) applications with a minimum
number of external components.
8
1
S
Q
Q2
Q1
R
170
Ω
7
Switch
Collector
2
Ipk Sense
Switch
Emitter
OSCILLATOR
6
3
V CC
Timing
Capacitor
COMPARATOR
1.25 V
REFERENCE
REGULATOR
Comparator
Inverting
Input
ELECTRICAL CHARACTERISTICS
Parameter
5
4
Gnd
(Test Parameters unless otherwise stated : VCC = 5V , TJ = 25°C)
Test Conditions
Min.
Typ.
Max.
Units
OSCILLATOR
Charging Current
VCC = 5 to 40V
20
35
50
µA
Discharge Current
VCC = 5 to 40V
150
200
250
µA
Voltage Swing
Discharge to Charge Current Ratio
Ipk(sense) = VCC
Current Limit Sense Voltage
Ichg = Idischg
250
0.5
Vpp
6.0
—
300
350
mV
1
1.3
V
0.45
0.7
V
OUTPUT SWITCH
Saturation Voltage, Darlington Connection * ISW = 1.0A
Saturation Voltage *
ISW = 1.0A
IC(Driver) = 50mA (Forced β = 20)
DC Current Gain
ISW = 1.0A , VCE = 5.0V
Collector Off–State Current
VCE = 40V
35
120
—
10
nA
COMPARATOR
Threshold Voltage *
1.18
Threshold Voltage Line Regulation *
VCC = 3 to 40V
Input Bias Current *
VIN = 0V
1.25
1.32
V
0.04
0.2
mV/V
40
400
nA
2.4
3.5
mA
TOTAL DEVICE
Supply Current *
VCC = 5 to 40V
CT = 0.001µF
Ipk(sense) = VCC
VPIN 5 > Vth
Pin 2 = Gnd , Remaining Pins Open.
NOTES
* Applies over full operating temperature range (see order information).
Semelab plc.
Telephone (01455) 556565. Telex: 341927. Fax (01455) 552612.
Prelim. 2/95
IP35063
IP33063
IP34063
DESIGN FORMULA TABLE
Calculation
tON
Step–Down
VOUT + VF
Step–Up
VOUT + VF - VIN(MIN)
tOFF
VIN(MAX) - VSAT - VOUT
VIN(MIN) - VSAT
1
1
fMIN
fMIN
(tON + tOFF)MAX
CT
10-5
4x
tON
Ipk(switch)
2 IOUT(MAX)
RSC
0.33 / Ipk(switch)
L(MIN)
CO
VIN(MAX) - VSAT - VOUT
Ipk(switch)
4 x 10-5 tON
2 IOUT(MAX)
tON(MAX)
tON + tOFF
tOFF
0.33 / Ipk(switch)
VIN(MIN) - VSAT
Ipk(switch)
tON(MAX)
Ipk(switch) (tON + tOFF)
IOUT tON
8 Vripple(p–p)
Vripple
KEY
VSAT
VF
— Saturation voltage of the output switch.
— Forward voltage drop of the ringback rectifier.
The following power supply characteristics must be chosen:–
VIN
VOUT
IOUT
fMIN
Vripple(p–p)
— Nominal input voltage. If this voltage is not constant, then use VIN(MAX) for step–down and VIN(Min) for
step–up converter.
R2
— Desired output voltage, VOUT = 1.25 1 +
.
R1
— Desired output current.
— Minimum desired output switching frequency at the selected values for VIN and IO.
— Desired peak–to–peak output ripple voltage. In practice, the calculated value will need to be increased
due to the capacitors 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.
Semelab plc.
(
)
Telephone (01455) 556565. Telex: 341927. Fax (01455) 552612.
Prelim. 2/95
IP35063
IP33063
IP34063
APPLICATIONS INFORMATION
Step–Down Converter
Step–Up Converter
L 170 µH
8
1
8
1
1 8 0Ω
S
Q
S
Q2
Q1
R
Q2
Q1
R
170
Ω
7
Q
2
170
Ω
7
Ipk
2
1N5819
Ip k
1N5822
OSCILLATOR
R SC
0.33 Ω
6
V IN
25V
CT
OSCILLATOR
R SC
0.22 Ω
3
V CC
1.25 V
REFERENCE
REGULATOR
100 µF
3
V CC
COMPARATOR
1.25 V
REFERENCE
REGULATOR
100 µF
CT
470pF
5
6
V IN
12V
L
220 µH
COMPARATOR
CT
4
CT
1 50 0p F
5
4
V OUT
V OUT
5.0V
500mA
R2
3.3K
R1
1.2K
CO
470 µF
28V
175 mA
R2
47K
R1
2 .2 K
CO
1500 µF
External Current Boost Connections for IC > 1.5A
Step–Down, External NPN Switch
8
Step–Up, External NPN Switch
1
S
8
S
Q1
R
2
Q1
170
Ω
7
V OUT
OSCILLATOR
V OUT
Q2
Q
R
170
Ω
7
2
OSCILLATOR
R SC
R SC
6
V IN
1
Q2
Q
3
6
V IN
COMPARATOR
3
COMPARATOR
1.25 V
REFERENCE
REGULATOR
1.25 V
REFERENCE
REGULATOR
5
4
5
Step–Down, External PNP Saturated Switch
Step–Up, External NPN Saturated Switch
1
8
S
170
Ω
7
S
Q1
R
1
8
VO U T
Q2
Q
4
Q1
R
2
1 70
Ω
7
VO U T
Q2
Q
2
R – 0 FOR
C O NS TA NT V IN
O S CILLA TO R
O SC ILL AT O R
RS C
VI N
R SC
6
3
V IN
6
C O M PA RA TO R
5
Semelab plc.
3
C O M PA RA TO R
1.2 5 V
R EF ER EN C E
RE G UL AT O R
1 .25 V
R EF ER EN CE
RE G UL ATO R
4
Telephone (01455) 556565. Telex: 341927. Fax (01455) 552612.
5
4
Prelim. 2/95
IP35063
IP33063
IP34063
TYPICAL PERFORMANCE CHARACTERISTICS
Standby Supply Current
vs Supply Voltage
1 00 0
3.2
V CC = 5V
500
C T = 0.001µF
Ipk(sense) = VCC
ICC SUPPLY CURRENT (mA)
OUTPUT SWITCH ON–OFF TIME (µs)
Output Switch On–Off Time
vs Oscillator Timing Capacitor
Pin 5 = Gnd
200
100
t on
50
t off
20
10
5
Ipk(sense) = VCC
Pin 2 = Gnd
2.4
1.6
0.8
2
0
1
0.1
0.2
0.5
CT
1
2
5
10
20
50
10 0
0
10
15
20
25
30
40
35
V CC SUPPLY VOLTAGE (V)
Emitter–Follower Configuration
Output Switch Saturation Voltage
vs Emitter Current
Common–Emitter Configuration
Output Switch Saturation Voltage
vs Collector Current
1.2
VCE(sat) SATURATION VOLTAGE (V)
1.6
VCE(sat) SATURATION VOLTAGE (V)
5
OSCILLATOR TIMING CAPACITOR (nF)
V CC = 5V
Pin 1,7,8 = VCC
Pin 3,5 = Gnd
1.5
1.4
1.3
1.2
1.1
1.0
V CC = 5V
Pin 7 = VCC
Pin 2,3,5 = G nd
1.0
DARLINGTON CONNECTION
0.8
0.6
FORCED β = 20
0.4
0.2
0
0
0.2
0.4
0.6
IE
Semelab plc.
0.8
1.0
1.2
1.4
0
0.2
EMITTER CURRENT (A)
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0.4
0.6
IC
0.8
1.0
1.2
1.4
COLLECTOR CURRENT (A)
Prelim. 2/95
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