AN3168

Examples of negative power supplies

Doc ID 17193 Rev 1

18/20

Figure 18.

Flyback power supply with VIPer16 device

For flyback converter design, please refer to the technical note TN0023 from

STMicroelectronics.

3.6

Comparison of negative power supplies

Table 6 summarizes the advantages and drawbacks of the negative power supplies

introduced in the point 3 according to the cost, the size, the easiness of implementation, the

standby power consumption, the output current capability and the capability to generate

easily one or more output voltages.

Q1

D4

R6

C2

Vdd

D1

C4

C5

R7

D5

AC mains

D3

C1

R2

L1

R3

LIM

COMP

VIPer16

D

Vdd

FB

C6

R5

R4

C3

D2

VDD

D6

Q1

D4

C2

Vdd

C4

C5

R7

D5

V

DD

AC mains

V

SS

D3

C1

L1

R1

R3

Control

VIPer16

D

S / GND

C6

C3

V

DD

Table 6.

Power supply

type

Cost

Size

Easy of

implementation

Standby power

consumption

Output

Max. current

level

Number

Linear

-

--

++

--

+

1 or more

Capacitive

+

-

++

-

--

1

Resistive

-

+

++

--

---

1

Buck-boost

++

++

+

+++

+++

1

Flyback

+

+

+

+++

++++

1 or more

1.

Key: +: good, -: bad