AN1695 - APPLICATION NOTE

2/5

Figure 2 : Typical application schematic

The list of components used in the typical application board is shown in the bill of material here below. All

other components are not mounted. Passive components like capacitors and resistors used in this

Evaluation Board are through-hole components to be more easily changed by the user. Of course, in

real-life application, surface-mounted devices will be used and the whole application can fit into a very

small PCB area.

Table 3 : Bill of material

Reference

Value

Description

Manufacturer

U1

TSM108ID

PWM controller

STMicroelectronics

Q4

STS3DPFS30

Mosfet + diode

STMicroelectronics

L1

P0250.154T

150µH - buck main inductor

Pulse

L

short circuit

filtering inductor

C1

220pF

oscillator capacitor

C2-C3

22nF

compensation capacitors

C4-C7

47µF-25V

buck input and output capacitors

Rubycon ZL

C10

100nF

voltage reference bias capacitor

R8-R17-R18-R19

1

Ω

shunt resistor

R6-R7

22k

Ω-10%

compensation resistors

R9

15k

Ω-1%

divider bridge upper resistor

R10

11k

Ω-1%

divider bridge lower resistor

R16-R22

short circuit

13

12

9

11

10

8

14

7

2

4

5

1

3

VS

ICTRL

ICOMP

VCOMP

VREF

VCTRL

200mV

2,52V

GND

6

G

VCC

!STBY

UV

OV

OSC

GD

TSM108

Vin

Vout

L1

U1

Q4-B

Q4-A

R7

R6

C3

C2

C4

C7

R9

R10

C10

C1

R17

R8

R18

R19