MC79xxCT Series
New Product
Vishay
formerly General Semiconductor
3-Terminal Fixed Negative Voltage Regulators
Pin Arrangement
Description
These voltage regulators are intended as complements to the popular MC78xx Series devices. These negative regulators 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 employ current limiting, thermal shutdown, and safe-area compensation – making them remarkably rugged under most operating conditions. With adequate heatsinking they can deliver output currents in excess of 1.5 ampere.
TO-220
1. Ground 3 2. Input 2 1 3. Output (heatsink connected to pin 2)
Standard Application
Features
Input
MC79xx
Output Co 0.1µF
• Output current in excess of 1.5 Ampere • No external components required • Internal thermal overload protection • Internal short-circuit current limiting • Output transistor safe-area compensation • Output voltage offered in 2% tolerance
Cin 0.33µF
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.
Mechanical Data
Case: TO-220 Package Weight: approx. 2.24g Case outline is on the back page
Internal Block Diagram
GND R1 R2 Reference Voltage
+ -Q1 Q2 Short Circuit Protection
Output
I1
I2
RSC Input
Document Number 74814 11-Jun-02
www.vishay.com 1
MC79xxCT Series
Vishay
formerly General Semiconductor
Maximum Ratings
Parameter Input Voltage Input Voltage
(1) (2) (3)
Ratings at 25°C ambient temperature unless otherwise specified.
Symbol Vin Vin PD TJ Tstg
Value – 30 – 40 15 – 20 to +150 – 65 to +150
Unit V V W °C °C
Power Dissipation
Operating Junction Temperature Range Storage Junction Temperature Range
Notes: (1) MC7905 to MC7918 (2) MC7924 (3) Follow the derating curve. When TJ exceeds 150°C, the internal circuit cuts off the output
Electrical Characteristics – MC7905
Vin = –10V, Iout = 500mA, Cin = 2µF, Cout = 1µF; TJ = 0°C to 125°C, unless otherwise noted. Parameter Symbol Test Circuit 1 Conditions TJ = 25°C Output Voltage Vo Vin = –7 to –20V, Io = 5mA to 1A Vin = –7 to –25V Vin = –8 to –12V Io = 5mA to 1.5A Io = 250mA to 750mA TJ = 25°C Vin = – 7 to – 25V Io = 5mA to 1A f = 10Hz to 100KHz Vin = –8 to –18V Io = 100mA, f = 120Hz Io = 1.0A, TJ = 25°C 1 1 TJ = 25°C Io = 5mA, TJ = 0 to125°C Min. – 4.90 –4.85 — — — — — — — — 62 — — — Typ. – 5.0 — 3 1 10 3 2 — — 40 74 1.1 2.1 – 0.4 Max. – 5.10 –5.15 100 50 100 50 4 1.3 0.5 — — — — — V Unit
Line Regulation (TJ = 25°C) Load Regulation (TJ = 25°C) Quiescent Current Quiescent Current Change (TJ = 25°C) Output Noise Voltage (TJ = 25°C) Ripple Rejection Ratio Dropout Voltage Peak Output Current Temp. Coefficient of Output Voltage
∆REG line ∆REG load Iq ∆Iq Vn RR Vdrop Io-peak ∆Vo/∆TA
1
mV
1 2 2 1 3
mV mA mA µV dB V A mV/°C 2 of 8
Note: Where the condition TJ = 25°C is specified, pulse testing (
