MC79xxCT Series
Vishay Semiconductor
Document Number 74814 www.vishay.com
29-Nov-01 1
New Product
3-Terminal Fixed Negative Voltage Regulators
Description
These voltage regulators are intended as complements
to the popular MC78xx Series devices .These negative reg-
ulators are available in the same seven-voltage options as
the MC78xx devices. In addition, one extra voltage
option commonly employed in MECL systems is also
available in the negative MC79xx Series.
Available in fixed output voltage options from –5.0 to –24
volts , these regulators emplo y current limiting, thermal shut-
down, and safe-area compensation – making them remark-
ably rugged under most operating conditions .With adequate
heatsinking they can deliver output currents in excess of
1.5 ampere.
Features
• Output current in excess of 1.5 Ampere
• No exter nal components required
• Internal ther mal overload protection
• Internal short-circuit current limiting
• Output transistor safe-area compensation
• Output voltage offered in 2% tolerance
Mechanical Data
Case: TO-220 Package
Weight: approx. 2.24g
Case outline is on the back page
Pin Arrangement
Input
Output
R1
R2
RSC
GND
Reference
Voltage
Short Circuit
Protection
+
-- Q1 Q2
I1 I2
Internal Block Diagram
Output
Input
Cin
0.33µF
MC79xx
Co
0.1µF
1. Ground
2. Input
3. Output
(heatsink connected to pin 2)
Standard Application
Notes:
A common ground is required between the input and the output voltages.
The input voltage must remain typically 2.0V more negative even during
the high point on the input ripple voltage.
xx = these two digits of the part number indicate output voltage.
Cin is required if regulator is located an appreciable distance from power
supply filter.
Co improves stability and transient response.
123
TO-220
MC79xxCT Series
Vishay Semiconductor
www.vishay.com Document Number 74814
229-Nov-01
Electrical Characteristics – MC7905
V
in
= –10V, I
out
= 500mA, C
in
= 2µF, C
out
= 1µF; T
J
= 0°C to 125°C, unless otherwise noted.
Parameter Symbol Test Conditions Min. Typ. Max. Unit
Circuit
TJ= 25°C–4.90 –5.0 –5.10 V
Output Voltage Vo 1 Vin = –7 to –20V, –4.85 —–5.15
Io = 5mA to 1A
Line Regulation ∆REGline 1Vin = –7 to –25V —3 100 mV
(TJ= 25°C) Vin = –8 to –12V —150
Load Regulation ∆REGload 1Io = 5mA to 1.5A —10 100 mV
(TJ= 25°C) Io = 250mA to 750mA —350
Quiescent Current Iq2T
J= 25°C—24mA
Quiescent Current Change ∆Iq2Vin = –7 to –25V ——1.3 mA
(TJ= 25°C) Io = 5mA to 1A ——0.5
Output Noise Voltage (TJ= 25°C) Vn1 f = 10Hz to 100KHz —40 —µV
Ripple Rejection Ratio RR 3 Vin = –8 to –18V 62 74 —dB
Io = 100mA, f = 120Hz
Dropout Voltage Vdrop Io = 1.0A, TJ= 25°C—1.1 —V
Peak Output Current Io-peak 1T
J= 25°C—2.1 —A
Temp. Coefficient of Output Voltage ∆Vo/∆TA1 Io=5mA, T J=0 to125°C—–0.4 —mV/°C
Note: Where the condition TJ= 25°C is specified, pulse testing (<10ms) with low duty cycle is required to maintain junction temperature stability.
Maximum Ratings Ratings at 25°C ambient temperature unless otherwise specified.
Parameter Symbol Value Unit
Input Voltage(1) Vin –30 V
Input Voltage(2) Vin –40 V
Power Dissipation(3) PD 15 W
Operating Junction Temperature Range TJ–20 to +150 °C
Storage Junction Temperature Range Tstg –65 to +150 °C
Notes: (1) MC7905 to MC7918
(2) MC7924
(3) Follow the derating curve.When TJexceeds 150°C, the inter nal circuit cuts off the output
2 of 8
MC79xxCT Series
Vishay Semiconductor
Document Number 74814 www.vishay.com
29-Nov-01 3
Electrical Characteristics – MC7906
V
in
= –11V, I
out
= 500mA, C
in
= 2µF, C
out
= 1µF; T
J
= 0°C to 125°C, unless otherwise noted.
Parameter Symbol Test Conditions Min. Typ. Max. Unit
Circuit
TJ= 25°C–5.88 –6.0 –6.12 V
Output Voltage Vo1Vin = –8 to –21V, –5.82 —–6.18
Io = 5mA to 1A
Line Regulation REGline 1Vin = –8 to –25V —4 120 mV
(TJ= 25°C) Vin = –9 to –13V —1.5 60
Load Regulation REGload 1Io = 5mA to 1.5A —10 120 mV
(TJ= 25°C) Io = 250mA to 750mA —360
Quiescent Current Iq2T
J= 25°C—24mA
Quiescent Current Change ∆Iq2Vin = –8 to –25V ——1.3 mA
(TJ= 25°C) Io = 5mA to 1A ——0.5
Output Noise Voltage (TJ= 25°C) Vn1 f = 10Hz to 100KHz —44 —µV
Ripple Rejection Ratio RR 3 Vin = –9 to –19V 60 73 —dB
Io = 100mA, f = 120Hz
Dropout Voltage Vdrop Io = 1.0A, TJ= 25°C—1.1 —V
Peak Output Current Io-peak 1T
J= 25°C—2.1 —A
Temp. Coefficient of Output Voltage ∆Vo/∆TA1 Io=5mA, TJ= 0 to125°C—–0.5 —mV/°C
Electrical Characteristics – MC7908
Vin = –14V, I
out
= 500mA, Cin = 2µF, C
out
= 1µF; T
J
= 0°C to 125°C, unless otherwise noted.
Parameter Symbol Test Conditions Min. Typ. Max. Unit
Circuit
TJ= 25°C–7.84 –8.0 –8.16 V
Output Voltage Vo1Vin = –10.5 to –23V, –7.76 —–8.24
Io = 5mA to 1A
Line Regulation REGline 1Vin = –10.5 to –25V —6 160 mV
(TJ= 25°C) Vin = –11 to –15V —280
Load Regulation REGload 1Io = 5mA to 1.5A —12 160 mV
(TJ= 25°C) Io = 250mA to 750mA —480
Quiescent Current Iq2T
J= 25°C—2.2 4.5 mA
Quiescent Current Change ∆Iq2Vin = –10.5 to –25V —— 1mA
(TJ= 25°C) Io = 5mA to 1A ——0.5
Output Noise Voltage (TJ= 25°C) Vn1 f = 10Hz to 100KHz —52 —µV
Ripple Rejection Ratio RR 3 Vin = –11 to –21V 56 71 —dB
Io = 100mA, f = 120Hz
Dropout Voltage Vdrop Io = 1.0A, TJ= 25°C—1.1 —V
Peak Output Current Io-peak 1T
J= 25°C—2.1 —A
Temp. Coefficient of Output Voltage ∆Vo/∆TA1 Io=5mA, T J=0 to125°C—–0.6 —mV/°C
MC79xxCT Series
Vishay Semiconductor
www.vishay.com Document Number 74814
429-Nov-01
Electrical Characteristics – MC7909
Vin = –15V, I
out
= 500mA, Cin = 2µF, C
out
= 1µF; T
J
= 0°C to 125°C, unless otherwise noted.
Parameter Symbol Test Conditions Min. Typ. Max. Unit
Circuit
TJ= 25°C–8.82 –9.0 –9.18 V
Output Voltage Vo1Vin = –11.5 to –24V, –8.73 —–9.27
Io = 5mA to 1A
Line Regulation REGline 1Vin = –11.5 to –27V —7 180 mV
(TJ= 25°C) Vin = –12 to –16V —290
Load Regulation REGload 1Io = 5mA to 1.5A —12 180 mV
(TJ= 25°C) Io = 250mA to 750mA —490
Quiescent Current Iq2T
J= 25°C—2.2 4.5 mA
Quiescent Current Change ∆Iq2Vin = –11.5 to –27V —— 1mA
(TJ= 25°C) Io = 5mA to 1A ——0.5
Output Noise Voltage (TJ= 25°C) Vn1 f = 10Hz to 100KHz —58 —µV
Ripple Rejection Ratio RR 3 Vin = –12 to –22V 56 71 —dB
Io = 100mA, f = 120Hz
Dropout Voltage Vdrop Io = 1.0A, TJ= 25°C—1.1 —V
Peak Output Current Io-peak 1T
J= 25°C—2.1 —A
Temp. Coefficient of Output Voltage ∆Vo/∆TA1 Io=5mA, TJ= 0 to125°C—0.6 —mV/°C
Electrical Characteristics – MC7912
Vin = –19V, I
out
= 500mA, Cin = 2µF, C
out
= 1µF; T
J
= 0°C to 125°C, unless otherwise noted.
Parameter Symbol Test Conditions Min. Typ. Max. Unit
Circuit
TJ= 25°C–11.76 –12.0 –12.24 V
Output Voltage Vo1Vin = –14.5 to –27V, –11.64 —–12.36
Io = 5mA to 1A
Line Regulation REGline 1Vin = –14.5 to –30V —10 240 mV
(TJ= 25°C) Vin = –15 to –19V —3 120
Load Regulation REGload 1Io = 5mA to 1.5A —12 240 mV
(TJ= 25°C) Io = 250mA to 750mA —4 120
Quiescent Current Iq2T
J= 25°C—2.5 5 mA
Quiescent Current Change ∆Iq2Vin = –14.5 to –30V —— 1mA
(TJ= 25°C) Io = 5mA to 1A ——0.5
Output Noise Voltage (TJ= 25°C) Vn1 f = 10Hz to 100KHz —75 —µV
Ripple Rejection Ratio RR 3 Vin = –15 to –25V 55 70 —dB
Io = 100mA, f = 120Hz
Dropout Voltage Vdrop Io = 1.0A, TJ= 25°C—1.1 —V
Peak Output Current Io-peak 1T
J= 25°C—2.1 —A
Temp. Coefficient of Output Voltage ∆Vo/∆TA1 Io=5mA, T J=0 to125°C—–0.8 —mV/°C
MC79xxCT Series
Vishay Semiconductor
Document Number 74814 www.vishay.com
29-Nov-01 5
Electrical Characteristics – MC7915
V
in
= –23V, I
out
= 500mA, C
in
= 2µF, C
out
= 1µF; T
J
= 0°C to 125°C, unless otherwise noted.
Parameter Symbol Test Conditions Min. Typ. Max. Unit
Circuit
TJ= 25°C–14.7 –15 –15.3 V
Output Voltage Vo1Vin = –17.5 to –30V, –14.55 —–15.45
Io = 5mA to 1A
Line Regulation REGline 1Vin = –17.5 to –30V —11 300 mV
(TJ= 25°C) Vin = –18 to –22V —3 150
Load Regulation REGload 1Io = 5mA to 1.5A —12 300 mV
(TJ= 25°C) Io = 250mA to 750mA —4 150
Quiescent Current Iq2T
J= 25°C—2.5 5 mA
Quiescent Current Change ∆Iq2Vin = –17.5 to –30V —— 1mA
(TJ= 25°C) Io = 5mA to 1A ——0.5
Output Noise Voltage (TJ= 25°C) Vn1 f = 10Hz to 100KHz —90 —µV
Ripple Rejection Ratio RR 3 Vin = –18 to –28V 54 69 —dB
Io = 100mA, f = 120Hz
Dropout Voltage Vdrop Io = 1.0A, TJ= 25°C—1.1 —V
Peak Output Current Io-peak 1T
J= 25°C—2.1 —A
Temp. Coefficient of Output Voltage ∆Vo/∆TA1 Io=5mA, TJ= 0 to125°C—0.9 —mV/°C
Electrical Characteristics – MC7918
V
in
= –27V, I
out
= 500mA, C
in
= 2µF, C
out
= 1µF; T
J
= 0°C to 125°C, unless otherwise noted.
Parameter Symbol Test Conditions Min. Typ. Max. Unit
Circuit
TJ= 25°C–17.64 –18.0 –18.36 V
Output Voltage Vo1Vin = –21 to –33V, –17.46 —–18.54
Io = 5mA to 1A
Line Regulation REGline 1Vin = –21 to –33V —15 360 mV
(TJ= 25°C) Vin = –22 to –26V —5 180
Load Regulation REGload 1Io = 5mA to 1.5A —12 360 mV
(TJ= 25°C) Io = 250mA to 750mA —4 180
Quiescent Current Iq2T
J= 25°C—2.5 5 mA
Quiescent Current Change ∆Iq2Vin = –21 to –33V —— 1mA
(TJ= 25°C) Io = 5mA to 1A ——0.5
Output Noise Voltage (TJ= 25°C) Vn1 f = 10Hz to 100KHz —110 —µV
Ripple Rejection Ratio RR 3 Vin = –21 to –31V 53 68 —dB
Io = 100mA, f = 120Hz
Dropout Voltage Vdrop Io = 1.0A, TJ= 25°C—1.1 —V
Peak Output Current Io-peak 1T
J= 25°C—2.1 —A
Temp. Coefficient of Output Voltage ∆Vo/∆TA1 Io=5mA, T J=0 to125°C—–1—mV/°C
MC79xxCT Series
Vishay Semiconductor
www.vishay.com Document Number 74814
629-Nov-01
Electrical Characteristics – MC7924
V
in
= –33V, I
out
= 500mA, C
in
= 2µF, C
out
= 1µF; T
J
= 0°C to 125°C, unless otherwise noted.
Parameter Symbol Test Conditions Min. Typ. Max. Unit
Circuit
TJ= 25°C–23.52 –24 –24.48 V
Output Voltage Vo1Vin = –26 to –38V, –23.28 —–24.72
Io = 5mA to 1A
Line Regulation REGline 1Vin = –26 to –38V —18 480 mV
(TJ= 25°C) Vin = –27 to –32V —6 240
Load Regulation REGload 1Io = 5mA to 1.5A —12 480 mV
(TJ= 25°C) Io = 250mA to 750mA —4 240
Quiescent Current Iq2T
J= 25°C—35mA
Quiescent Current Change ∆Iq2Vin = –26 to –38V —— 1mA
(TJ= 25°C) Io = 5mA to 1A ——0.5
Output Noise Voltage (TJ= 25°C) Vn1 f = 10Hz to 100KHz —170 —µV
Ripple Rejection Ratio RR 3 Vin = –26 to –36V 50 65 —dB
Io = 100mA, f = 120Hz
Dropout Voltage Vdrop Io = 1.0A, TJ= 25°C—1.1 —V
Peak Output Current Io-peak 1T
J= 25°C—2.1 —A
Temp. Coefficient of Output Voltage ∆Vo/∆TA1 Io=5mA, TJ= 0 to125°C—–1—mV/°C
Io
+2
13
MC79xx
V
Test Circuit 1
Io
2
13
MC79xx
V
Io
1µF
2
13
MC79xx
A
Test Circuit 2
Test Circuit 3
2µF
+
+
2µF
1µF
+
1µF
+
+
2µF
MC79xxCT Series
Vishay Semiconductor
Document Number 74814 www.vishay.com
29-Nov-01 7
Ratings and
Characteristic Curves(TA= 25°C unless otherwise noted)
20
10
1.0
25 50 75 100 125 150
Fig. 1 – Power Dissipation vs.
Ambient Temperature
PO -- Power Dissipation (W)
TA -- Ambient Temperature (°C)
0.1
0 6.0 12 18 24 30
Fig. 3 – Peak Output Current
Io -- Output Current (A)
Input -- Output Voltage Differential (V)
1.0
2.0
2.5
0.5
1.5
10 100 1.0K 10K 100K
RR -- Ripple Rejection (db)
f -- Frequency (HZ)
20
0
40
60
80
100
4.0 8.0 12 16 20 24
Fig. 5 – Ripple Rejection
vs. Output Voltage
RR -- Ripple Rejection (db)
Vo -- Output Voltage (V)
40
70
50
60
80
0
Infinite Heatsink
θHS = 5°C/W
θHS = 15°C/W
No Heatsink
θJC = 5°C/W
θJA = 65°C/W
PD(max) = 15W
6.06
6.10
6.14
6.18
6.22
6.26
--25 0 25 50 75 100 125 150 175
Fig. 6 – Output Voltage
vs. Junction Temperature
VO -- Output Voltage (-V)
TJ -- Junction Temperature (°C)
250 50 75 100 125
Fig. 2 – Quiescent Current
IIB -- Input Bias Current (mA)
TJ -- Junction Temperature (°C)
Fig. 4 –Ripple Rejection Ratio
vs. Frequency
Vin = --11V
Vo = --6.0V
Io = 20mA
Vin = --11V
Vo = --6.0V
Io = 20mA
f = 120Hz
Io = 20mA
Vin = 1.0V(RMS)
1.8
1.9
2.0
Vin = -11V
VO = -6.0V
IO = 20mA
MC79xxCT Series
Vishay Semiconductor
www.vishay.com Document Number 74814
829-Nov-01
13.9 ± 0.41
2.53 ± 0.185
3.84 ± 0.6 Dia.
10.25 ± 0.25
28.7 ± 0.92
3.94 ± 0.375
2.69 ± 0.25
0.8 ± 0.12
1.3 ± 0.185
1.27 ± 0.12
2.55 ± 0.375
4.85 ± 0.375
0.387 ± 0.09
8.54 ± 0.26
6.26 ± 0.25
14.8 ± 0.51
TO-220 Case Outline
Dimensions in
millimeters
