DEIC420 - IXYS Corporation

Features

• Built using the advantages and compatibility

of CMOS and IXYS HDMOSTM processes

• Latch-Up Protected

• High Peak Output Current: 20A Peak

• Wide Operating Range: 8V to 30V

• Rise And Fall Times of <4ns

• Minimum Pulse Width Of 8ns

• High Capacitive Load

Drive Capability: 4nF in <4ns

• Matched Rise And Fall Times

• 32ns Input To Output Delay Time

• Low Output Impedance

• Low Quiescent Supply Currentt

Applications

• Driving RF MOSFETs

• Class D or E Switching Amplifier Drivers

• Multi MHz Switch Mode Power Supplies (SMPS)

• Pulse Generators

• Acoustic Transducer Drivers

• Pulsed Laser Diode Drivers

• DC to DC Converters

• Pulse Transformer Driver

20 Ampere Low-Side Ultrafast RF MOSFET Driver

First Release

Description

TheDEIC420 is a CMOS high speed high current gate

driver specifically designed to drive MOSFETs in Class D

and E HF RF applications at up to 45MHz, as well as

other applications requiring ultrafast rise and fall times or

short minimum pulse widths. The DEIC420 can source

and sink 20A of peak current while producing voltage rise

and fall times of less than 4ns, and minimum pulse

widths of 8ns. The input of the driver is compatible with

TTL or CMOS and is fully immune to latch up over the

entire operating range. Designed with small internal

delays, cross conduction/current shoot-through is

virtually eliminated in the DEIC420. Its features and wide

safety margin in operating voltage and power make the

DEIC420 unmatched in performance and value.

The DEIC420 is packaged in DEI's low inductance RF

package incorporating DEI's patented (1) RF layout

techniques to minimize stray lead inductances for

optimum switching performance. For applications that do

not require the power dissipation of the DEIC420, the

driver is also available in a 28 pin SOIC package. See

the IXDD415SI data sheet for additional information. The

DEIC420 is a surface-mount device, and incorporates

patented RF layout techniques to minimize stray lead

inductances for optimum switching performance.

(1) DEI U.S. Patent #4,891,686

DEIC420

Figure 1 - DEIC420 Functional Diagram

DEIC420

Unless otherwise noted, TA = 25 oC, 8V ≤ VCC ≤ 30V .

All voltage measurements with respect to DGND. DEIC420 configured as described in Test Conditions.

Electrical Characteristics

Symbol Parameter Test Conditions Min Typ Max Units

VIH High input voltage 3.5 V

VIL Low input voltage 0.8 V

VIN Input voltage range -5 VCC + 0.3 V

IIN Input current 0V ≤ VIN ≤ VCC

-10 10

µA

VOH High output voltage VCC - .025 V

VOL Low output voltage 0.025 V

ROH Output resistance

@ Output high

IOUT = 10mA, VCC = 15V

0.4 0.6

Ω

ROL Output resistance

@ Output Low

IOUT = 10mA, VCC = 15V 0.4 0.6 Ω

IPEAK Peak output current VCC = 15V

20 A

IDC Continuous output

current

4 A

fMAX Maximum frequency CL=4nF Vcc=15V 45 MHz

tR Rise time

(1) C

L=1nF Vcc=15V VOH=2V to 12V

CL=4nF Vcc=15V VOH=2V to 12V

tF Fall time

(1) C

L=1nF Vcc=15V VOH=12V to 2V

CL=4nF Vcc=15V VOH=12V to 2V

3.5

tONDLY On-time propagation

delay (1)

CL=4nF Vcc=15V 32 38 ns

tOFFDLY Off-time propagation

delay (1)

CL=4nF Vcc=15V 29 35 ns

PWmin Minimum pulse width FWHM CL=1nF Vcc=15V

+3V to +3V CL=1nF Vcc=15V

VCC Power supply voltage 8 15 30 V

ICC Power supply current VIN = 3.5V

VIN = 0V

VIN = + VCC

µA

Absolute Maximum Ratings

Parameter

alue

Supply Voltage 30V

All Other Pins -0.3V to VCC + 0.3V

Power Dissipation

TAMBIENT ≤25 oC 2W

TCASE ≤25 oC 100W

Storage Temperature -65oC to 150oC

Soldering Lead Temperature

(10 seconds maximum) 300oC

Parameter

alue

Maximum Junction Temperature 150oC

Operating Temperature Range -40oC to 85oC

Thermal Impedance (Junction To Case)

θJC 0.13oC/W

(1) Refer to Figures 3a and 3b

Specifications Subject To Change Without Notice

DEIC420

Lead Description - DEIC420

SYMBOL FUNCTION DESCRIPTION

VCC Supply Voltage

Positive power-supply voltage input. These leads provide power to

the entire chip. The range for this voltage is from 8V to 30V.

IN Input Input signal-TTL or CMOS compatible.

OUT Output

Driver Output. For application purposes, this lead is connected,

directly to the Gate of a MOSFET

GND Power Ground

The system ground leads. Internally connected to all circuitry, these

leads provide ground reference for the entire chip. These leads

should be connected to a low noise analog ground plane for

optimum performance.

Note 1: Operating the device beyond parameters with listed “absolute maximum ratings” may cause permanent

damage to the device. Typical values indicate conditions for which the device is intended to be functional, but do not

guarantee specific performance limits. The guaranteed specifications apply only for the test conditions listed.

Exposure to absolute maximum rated conditions for extended periods may affect device reliability.

CAUTION: These devices are sensitive to electrostatic discharge; follow proper ESD procedures

when handling and assembling this component.

Figure 2 - DEIC420 Package Photo And Outline

Figure 3a - Characteristics Test Diagram Figure 3b - Timing Diagram

INPUT

OUTPUT

90%

2.5V

10%

Vcc

90%

10%

ONDLY

OFFDLY

MIN

DEIC420

Fall Time vs. Load Capacitance

CC = 15V, VOH = 12V To 2V

Load Capacitance (pF)

1k 2k 3k 4k0

Fall Time (ns)

Fig. 5

Rise Time vs. Load Capacitance

CC = 15V, VOH = 2V To 12V

Load Capacitance (pF)

1k 2k 3k 4k0

Rise Time (ns)

Fig. 4

Typical Performance Characteristics

Propagation Delay Times vs. Input Voltage

CL=4nF VCC=15V

Input Voltage (V)

24681012

Propagation Delay (ns)

tONDLY

tOFFDLY

Fig. 8 Propagation Delay Times vs. Junction Temperature

CL = 4nF, VCC = 15V

Tem

erature

(

°C

)

-40-20 0 20406080100120

Time (ns)

tOFFDLY

tONDLY

Fig. 9

Supply Current vs. Frequency

Vcc=15V

Frequency (MHz)

10 20 30 40

Supply Current (A)

4 nF

2 nF

1 nF

L = 0

Fig. 6 Supply Current vs. Load Capacitance

Vcc=15V

Load Capacitance (pF)

0k 1k 2k 3k 4k

Supply Current (A)

0.1

1 MHz

5 MHz

10 MHz

20 MHz

30 MHz

40 MHz

Fig. 7

DEIC420

Propagation Delay vs. Supply Voltage

=4nF VIN=5V@100kHz

Supply Voltage (V)

8 1012141618

Propagation Delay (ns)

tONDLY

tOFFDLY

Fig. 10

Typical Output Waveforms

Unless otherwise noted, all waveforms are taken driving a 1nF load, 1MHz repetition frequency, VCC=15V, Case Temperature = 25°C

Figure 11 3ns Rise Time Figure 12 3ns Fall Time

Figure 13 <8ns Minimum Pulse Width Figure 14 1MHz CW Repetition Frequency

DEIC420

Figure 15 13.56MHz CW Repetition Frequency Figure 16 50MHz Burst Repetition Frequency

Figure 17 - High Frequency Gate Drive Circuit

DEIC420

APPLICATIONS INFORMATION

High Frequency Gate Drive Circuit

The circuit diagram in figure 17 is a circuit diagram for a

very high switching speed, high frequency gate driver

circuit using the DEIC420. This is the circuit used in the

EVIC420 Evaluation Board,and is capable of driving a

MOSFET at up to the maximum operating limits of the

DEIC420. The circuit's very high switching speed and

high frequency operation dictates the close attention to

several important issues with respect to circuit design.

The three key elements are circuit loop inductance, Vcc

bypassing and grounding.

Circuit Loop Inductance

Referring to Figure 17, the Vcc to Vcc ground current

path defines the loop which will generate the inductive

term. This loop must be kept as short as possible. The

output lead must be no further than 0.375 inches

(9.5mm) from the gate of the MOSFET. Furthermore the

output ground leads must provide a balanced symmetric

coplanar ground return for optimum operation.

Vcc Bypassing

In order for the circuit to turn the MOSFET on properly,

the DEIC420 must be able to draw up to 20A of current

from the Vcc power supply in 2-6ns (depending upon the

input capacitance of the MOSFET being driven). This

means that there must be very low impedance between

the driver and the power supply. The most common

method of achieving this low impedance is to bypass the

power supply at the driver with a capacitance value that

is at least two orders of magnitude larger than the load

capacitance. Usually, this is achieved by placing two or

three different types of bypassing capacitors, with

complementary impedance curves, very close to the

driver itself. (These capacitors should be carefully

selected, low inductance, low resistance, high-pulse

current-service capacitors). Care should be taken to

keep the lengths of the leads between these bypass

capacitors and the DEIC420 to an absolute minimum.

The bypassing should be comprised of several values of

chip capacitors symmetrically placed on ether side of

the IC. Recommended values are .01uF, .47uF chips

and at least two 4.7uF tantalums.

Grounding

In order for the design to turn the load off properly, the

DEIC420 must be able to drain this 20A of current into

an adequate grounding system. There are three paths for

returning current that need to be considered: Path #1 is

between the DEIC420 and its load. Path #2 is between

the DEIC420 and its power supply. Path #3 is between

the DEIC420 and whatever logic is driving it. All three of

these paths should be as low in resistance and

inductance as possible, and thus as short as practical.

Output Lead Inductance

Of equal importance to supply bypassing and grounding

are issues related to the output lead inductance. Every

effort should be made to keep the leads between the

driver and its load as short and wide as possible, and

treated as coplanar transmission lines.

In configurations where the optimum configuration of

circuit layout and bypassing cannot be used, a series

resistance of a few Ohms in the gate lead may be

necessary to prevent ringing.

Heat Sinking

For high power operation, the bottom side metalized

substrate should be placed in compression against an

appropriate heat sink. The substrate is metalized for

improved heat dissipation, and is not electrically

connected to the device or to ground.

See the DEI technical note "DE-Series MOSFET and IC

Mounting Instructions" on the DEI web site at

www.directedenergy.com/apptech.htm for detailed

mounting instructions. The package dimensions of the

DEIC420 are identical to those of the DE-275 MOSFET.

Directed Energy, Inc.

An IXYS Company

2401 Research Blvd. Ste. 108, Ft. Collins, CO 80526

Tel: 970-493-1901; Fax: 970-493-1903

e-mail: deiinfo@directedenergy.com

www.directedenergy.com

Doc #9200-0230 Rev 3