IRDC3039EVAL
1
Rev. 1.0
05/30/03 www.irf.com
SPECIFICATION DATAINTRODUCTION
IRU3039 EVALUATION BOARD USER GUIDE
INPUT/OUTPUT CONNECTIONS
The IRU3039 controller IC is designed to provide a syn-
chronous Buck regulator and is targeted for applications
where the cost and size is critical. The IRU3039 oper-
ates with a single input supply up to 20V. The output
voltage can be programmed as low as 0.8V for low volt-
age applications. Selectable current limit is provided to
tailor to external MOSFET’s on-resistance for optimum
cost and performance. The IRU3039 features an uncom-
mitted error amplifier for tracking output voltage and is
capable of sourcing or sinking current for applications
such as DDR bus termination.
This device features a programmable switching frequency
set from 200KHz to 400KHz, under-voltage lockout for
both Vcc and Vc supplies, an external programmable
soft-start function as well as output under-voltage detec-
tion that latches off the device when an output short is
detected.
Switcher:
VIN = 18V
VOUT = 3.3V
IOUT = 8A
DVOUT = 100mV
FS = 200KHz
The following is the input/output connections:
Inputs:
JP1: Input (+18V), Gnd
Outputs:
JP2: VOUT (+3.3V), Gnd
The connection points is shown in Figure 1. Connect the
power supply cables according to this figure, minimize
wire lengths to reduce losses in the wire. Test point J1
provides easy connections for the oscilloscope voltage
probe to monitor the output voltage.
2Rev. 1.0
05/30/03
IRDC3039EVAL
www.irf.com
Figure 1 - Connection diagram of evaluation-board for IRU3039.
CONNECTION DIAGRAM
Power Supply
Gnd+20V
6A Supply
Load
0 - 8A
IRDC3039EVAL
3
Rev. 1.0
05/30/03 www.irf.com
The four layers for IRU3039 evaluation board are shown
in Figures 2.1-2.4. The input capacitors are all located
close to the MOSFETs. All the decoupling capacitors,
charge pump capacitor and feedback components are
located close to IC. The feedback resistors are tied to
the output voltage at the point of regulation.
The middle layers are dedicated to Power Ground and
Analog Ground. Analog Ground is kept separated from
the Power Ground and it is connected at a single point
as shown in figure 2.1.
LAYOUT
Figure 2.1 - Top layer of evaluation-board for IRU3039.
4Rev. 1.0
05/30/03
IRDC3039EVAL
www.irf.com
Figure 2.2 - Middle layer 1. Figure 2.3 - Middle layer 2.
Figure 2.4 - Bottom layer.
PGnd AnGnd PGnd
IRDC3039EVAL
5
Rev. 1.0
05/30/03 www.irf.com
SCHEMATIC
Figure 3 - Schematic of evaluation-board for IRU3039.
VREF NC NC NC
VCC
12345
LDRV
PGND
NC
GND
HDRV
VCOCSET
SS / SD
COMP
FB
VP
NC NCRTVO2
U1
IRU3039
R11
0V
R12
Open
R13
Open
R7
14K
C7C2C6
VDDQ
C1
15uF
JP1
R6
6
7
8
9
10
1112131415
16
17
18
19
20
L1
1uH
C13A
1uF R3
R4
R5
D2
BAT54
Q2
IRF7458
Q1
IRF7466
C8
470pF
R8
4.7V
C2A C2B C2C
C9A C9B C9C C12
L2
4.7uH
JP2
VOUT
GND
C13
1uF
R9
3.16K
R10
1K
D1
BAT54S
R14
Open
R2
R1
C3
1uF
C5
C10
0.1uF C11
1uF
Open 1uF
330uF
40mV330uF
40mV
15uF
25V 15uF
25V 15uF
25V
0V
Open
0V
5.76K
0V
0.1uF 5600pFOpen
Open
J1
VIN
GND
6Rev. 1.0
05/30/03
IRDC3039EVAL
www.irf.com
BILL OF MATERIAL
Ref Desig Description Value Qty Part# Manuf Web site (www.)
1
1
1
1
1
1
1
4
3
1
1
2
4
1
1
1
1
1
1
4
5
2
2
1
Q1
Q2
U1
D1
D2
L1
L2
C1,C2A,B,C
C5,6,10
C7
C8
C9A,B
C3,11,12,13
C13A
R4
R7
R8
R9
R10
R1,3,5,11
R2,6,12,13,14
C2,C9C
JP1,JP2
J1
MOSFET
MOSFET
Controller
Schottky Diode
Schottky Diode
Inductor
Inductor
Cap, Poscap
Capacitor
Capacitor
Capacitor
Cap, Poscap
Capacitor
Capacitor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Resistor
Capacitor
Connector
Scope Probe
IRF7466
IRF7458
IRU3039
BAT54S
BAT54
DS1608C-102
DO5022P-472HC
25TQC15M
ECJ-2VF1E104Z
ECU-V1H562KBG
ECJ-2VC1H471J
6TPB-330M
ECJ-2VF1C105Z
ECJ-3YB1E105K
ED1973-ND
131-50310-00
IR
IR
IR
IR
IR
Coilcraft
Coilcraft
Sanyo
Panasonic
Panasonic
Panasonic
Sanyo
Panasonic
Panasonic
Digikey
Textronix
irf.com
coilcraft.com
sanyo.com
maco.panasonic.co.jp
sanyo.com
maco.panasonic.co.jp
30V, 12.5mV, 11A
30V, 8mV, 14A
Synchronous PWM
Fast Switching
Fast Switching
1mH, 3A
4.7mH, 13A
15mF, 25V
0.1mF, Y5V, 25V
5600pF, X7R, 50V
470pF, X7R, 50V
330uF, 40mV
1mF, Y5V, 16V
1mF, X7R, 25V
5.76K, 1%
14K, 1%
4.7V, 1%
3.16K, 1%
1K, 1%
0V
Open(NA)
Open
2 Positive Terminal
IRDC3039EVAL
7
Rev. 1.0
05/30/03 www.irf.com
TYPICAL OPERATING CHARACTERISTICS
Test Conditions:
VIN=20V, VOUT=3.3V, IOUT=0-8A, Fs=200KHz
Figure 5 - Soft-Start.
Ch1: VIN, Ch2: VOUT, Ch3: VOUT2, Ch4: Vss
Figure 7 - Output Ripple.
Ch1: Output Ripple, Ch2: HDrv, Ch3: LDrv,
Ch4: Inductor Current
Figure 6 - Soft-Start pin grounded.
Ch1: HDrv, Ch2: LDrv
Figure 4 - Normal condition at No Load.
Ch1: HDrv, Ch2: LDrv, Ch4: Inductor Current
8Rev. 1.0
05/30/03
IRDC3039EVAL
www.irf.com
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TAC Fax: (310) 252-7903
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Data and specifications subject to change without notice. 02/01
Figure 10 - Efficiency Measurement.
VIN=20V, VOUT=3.3V
TYPICAL OPERATING CHARACTERISTICS
Test Conditions:
VIN=20V, VOUT=3.3V, IOUT=0-8A, Fs=200KHz
Figure 8 - Output shorted at start up.
Ch1: VOUT, Ch3: Vss, Ch4: Inductor Current Figure 9 - Load Transient Response
Ch1: VOUT, Ch3: Output Current
0A
8A
70
72
74
76
78
80
82
84
86
88
90
01234567891011
Output Current (A)
Efficiency (%)