EVAL5983

Data Brief
For further information contact your local STMicroelectronics sales office.
March 2009 Rev 1 1/6
6
Features
1.5 A DC output current
2.9 V to 18 V input voltage
Output voltage adjustable from 0.6 V to 16 V
250 kHz switching frequency, programmable
up to 1 MHz
Internal soft-start and inhibit
Low dropout operation: 100 % duty cycle
Zero-load current operation
Over-current and thermal protection
VFQFPN8 3 mm x 3 mm package
Description
The EVAL5983 demonstration board provides the
design engineer with a fully functional step-down
switching regulator with an output current of up to
1.5 A. The L5983 integrates STMicroelectronics
step-down switching regulator, together with all
the external components required for a typical
application.
The rated voltage of the input capacitor and the
Schottky diode rectifier repetitive peak reverse
voltage are both 25 V, making the board capable
of covering the entire 2.9 V - 18 V input voltage
range of the L5983 device.
The board features an external resistor divider
(R1 and R2) designed for an output voltage
of 3.3 V.
The output voltage can be set to a level from 0.6 V
up to the rated voltage of the output capacitor
(16 V).
The compensation network on the demonstration
board allows the use of MLCC as output filter to
keep the loop stable. The inductor saturation
current and forward current of the Schottky diode
are within the current limit values.
The switching frequency on the demonstration
board is set to 500 kHz by means of the R5
resistor connected to pin Fsw.
EVAL5983
EVAL5983
1.5 A step-down switching regulator demonstration board
based on the L5983
www.st.com
EVAL5983 EVAL5983 application circuit and component list
2/6
1 EVAL5983 application circuit and component list
Figure 1. Application circuit
Table 1. Component list
Reference Part number Description Manufacturer
C1 GRM31CR61E106KA12 10 μF, 25 V MURATA
C2 GRM31CR61C226KE15B 22 μf, 16 V MURATA
C3 2.2 nF, 50 V
C4 10 nF, 50 V
C5 220 pF, 50 V
C6 68 nF, 25 V
R1 4.99 kΩ, 1 %, 0.1 W 0603
R2 1.1 kΩ, 1 %, 0.1 W 0603
R3 330 Ω, 1 %, 0.1 W 0603
R4 2.99 kΩ, 1 %, 0.1 W 0603
R5 100 kΩ, 1 %, 0.1 W 0603
L1 7447779006 6.8 uH, 30 %, 2.91 A Coilcraft
D1 STPS2L25V 2 A, 2 5V STMicroelectronics
OUT
FB
SYNCH
INH
GND
COMP
VCC
L5985
C1
10uF
C4 10nF
R1 4.99K
R2 1.1K
D1
STPS2L25U
L1 6.8uH
C3 2.2nFR3 330
C5 220pF
R4 2.49K
FSW
8
3
7
6
4
5
2
1
C2
22uF
C6
68nF
COMP
1
Vout=3.3V
VIN=3.3V to 18V
R5 100K
OUT
FB
SYNCH
INH
GND
COMP
VCC
L5983
C1
10uF
C4 10nF
R1 4.99K
R2 1.1K
D1
STPS2L25U
L1 6.8uH
C3 2.2nFR3 330
C5 220pF
R4 2.49K
FSW
8
3
7
6
4
5
2
1
C2
22uF
C6
68nF
COMP
1
Vout=3.3V
VIN=3.3V to 18V
OUT
FB
SYNCH
INH
GND
COMP
VCC
L5985
C1
10uF
C4 10nF
R1 4.99K
R2 1.1K
D1
STPS2L25U
L1 6.8uH
C3 2.2nFR3 330
C5 220pF
R4 2.49K
FSW
8
3
7
6
4
5
2
1
C2
22uF
C6
68nF
COMP
1
Vout=3.3V
VIN=3.3V to 18V
R5 100K
OUT
FB
SYNCH
INH
GND
COMP
VCC
L5983
C1
10uF
C4 10nF
R1 4.99K
R2 1.1K
D1
STPS2L25U
L1 6.8uH
C3 2.2nFR3 330
C5 220pF
R4 2.49K
FSW
8
3
7
6
4
5
2
1
C2
22uF
C6
68nF
COMP
1
Vout=3.3V
VIN=3.3V to 18V
EVAL5983 PCB layout
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2 PCB layout
Figure 2. PCB layout (component side)
Figure 3. PCB layout (bottom side)
Figure 4. PCB layout (front side)

EVAL5983

Mfr. #:
Manufacturer:
STMicroelectronics
Description:
Power Management IC Development Tools 1.5A Step-Down L5983 EVAL BRD
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
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