Application Note 13 Issue 2 January 1996
The ZCN0545A and ZCP0545A Low Power IGBTs A Silicon/ Package Efficient Device for Compact Fluorescent Lamp (CFL) Ballasts and Static Switching David Bradbury
IGBT Characteristics The N-Type ZCN0545A and P-Type ZCP0545A are Insulated Gate Bipolar Transistors (IGBTs) available in the E-Line (TO92 compatible) package. The ZCN0545A is a 450V, 2A peak device and the ZCP0545A is a 450V, 0.8A peak device. With these devices Zetex has brought the advantages given by IGBTs to lower power and lower cost applications. applications. (Please refer to Appendix A for summarised datasheet information). information). IGBTs behave like a Darlington structure, utilising a MOSFET input device followed by a bipolar amplifier. The circuit symbols of the ZCN0545A and ZCP0545A are shown in Figure 1 and a simplified equivalent circuit for each is shown in Figure 2.
3) Like a bipolar Darlington, the device needs a drain-source voltage of greater than 0.7V before 0.7V before current flows.
ZCN0545
ZCP0545 C
G
E
G E
C
Figure 1 IGBT Symbols.
ZCN0545
ZCP0545 C
C
The most important characteristics of IGBTs are:1) MOSFET type input resistance, resistance , ideal for direct drive from microcontrollers. 2) Low RDS(on). For a given chip size and BVDSS the RDS(on) of an IGBT is less than 10% of a standard high voltage MOSFET at high current.
G G E
E
Figure 2 Conceptual Equivalent Circuit of the IGBT.
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Application Note 13 Issue 2 January 1996 protection. Transient protection for the design in Figure 8 is provided by D5 and BD1.
+12V
Lamp
ZCN0545A for Automotive Lamp and Relay Drivers.
+5V
Automotive lamp and relay drivers have to withstand extreme operating conditions. Behind an instrument panel temperatures can vary from a low of -40°C to over +85°C. Such drivers may have to withstand reverse battery connection, 24V rapid battery charging, a 100-240V 0.5J +ve transient, an 80V 50J load dump transient, and a number of other lower energy supply transients. The driver device will pass many times the normal load current if enabled during a supply transient. Consequently few driver transistors can be used without extensive transient and reverse supply protection. The ZCN0545A is an ideal driver for low power automotive lamps and relays. Its high BV DSS rating allows it to withstand all standard positive transients without further protection, and a 30V BV S D capability ensures survival of reverse battery connection without protection.
0V Figure 9 Simple IGBT Bulb Driver. In Figure 10, a high value low power resistor is connected across the relay coil to suppress transients generated by the relay during turn-off. Apart from this, no protection components are required for either circuit. This greatly reduces the cost of the driver circuits and saves on board space. +12V
+5V Figures 9 and 10 show all that is required to drive lamp and relay loads direct from 5V logic using the ZCN0545A. Although the on-voltage drop of the IGBT may at first seem high compared with a standard bipolar or MOSFET solution, when the losses caused by series connected reverse supply protection diodes and other suppressors are allowed for, the drops are comparable. In the E-Line (TO92 compatible) package the ZCN0545A will switch lamps and relay loads up to 180mA.
ZCN 0545A
Logic
R1 470
Logic
Relay
ZCN 0545A
0V Figure 10 Simple IGBT Relay Driver.
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Application Note 13 Issue 2 January 1996
Appendix A ZCN0545A and ZCP0545A Summary Data-Sheet ABSOLUTE MAXIMUM RATINGS ZCN0545A
ZCP0545A
UNIT
V DS
450
-450
V
Reverse Drain Source Voltage
VSD
30
-20
V
Continuous Drain Current
ID
0.32
-0.32
A
Pulsed Dra in Curr ent
IDMR IDM
2 1
-0.8 -0.4
A A
PARAMETER
SYMBOL
Forward Drain-Source Voltage
@ Tamb=25°C @ T amb=125°C
Gate-Source Voltage
V GS
±20
V
Power Dissipation
P tot
0.6
W
Operating and Storage Temperature Range
Tj:Tstg
-55 to +125
°C
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Application Note 13 Issue 2 January 1996
ELECTRICAL CHARACTERISTICS (at T amb = 25°C unless otherwise stated) ZCN0454A
ZCP0545A UNIT
PARAMETER
SYMBOL
Forward Drain-Source Breakdown Voltage
BV DSS
450
-450
V
VGS=0V
Reverse Drain-Source Breakdown Voltage (4)
BV SD
30
-20
V
ID=1mA
Gate-Source Threshold Voltage
V GS(th)
1
-3.5
V
ID =1mA, VDS= V GS
Zero Gate Voltage Drain Current
IDSS
-20 -2000
µA µA
VDS=450V, VGS=0V VDS=360V, VGS=0V, T=125°C (2)
Drain Source Saturation Voltage (1)
V DS(SAT)
3 3
-3 -3
V V
ID=500mA, VDS=10 V ID=250mA, VDS=5 V
Static Drain-Source On-State Resistance (1)
R DS(on)
6
6
Ω
VGS=10V,ID=0.5A
Input Capacitance (2)
C iss
90
120
pF
VDD ≈25V, VGS=0V, f=1MHz
Switching Times (2)(3)
ton
150
150
ns
toff
300
350
ns
VDD ≈25V, VGEN=10V I D=1A, RGS=50 Ω
MIN.
MAX.
3
MIN.
-1
10 400
MAX.
CONDITIONS.
1) Measured under pulsed conditions. Pulse width=300 µs. Duty cycle ≤2% (2) Sample test. (3) Switching times measured with 50 Ω source impedance and <5ns rise time on a pulse generator. (4) One minute maximum duration. Exceeds common in ternational automotive reverse battery test specifications. Please refer to datasheets for full device characterisation.
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