NCN6010

http://onsemi.com

11

Figure 10. Basic Charge Pump Operating Timings

S1

S2

S3

S4

S5

When the NCN6010 is programmed in the 5.0 V output

voltage, the clocks are activated, switch S5 is disconnected

and the output voltage is the result of the C1 charge transfer

into the output load. The current is limited by three mains

parameters:

− the Ron of the switching MOS (S1 through S4)

− the operating frequency

− the C1/C2 ratio and their ESR

The first parameters are depending upon the internal

structure and size of the NMOS/PMOS devices used to

design the chip. The third parameter is adjustable by the user

and, beside the micro farad values, the type of capacitors

plays a significant role. As a matter of fact, using a low cost

electrolytic model will ruin the efficiency due to the high

ESR of such a capacitor. It is highly recommended to use

ceramic types, preferably from the X5R or X7R series, to

achieve the efficiency and the SIM_VCC output voltage

ripple. Table 2 summarizes the characteristics of the most

common type of capacitors.

Table 2. Comparison of Capacitor Types

Manufacturers

Type/Serie

Format

Max Value

Tolerance

Typ. Z @ 500 kHz

MURATA

CERAMIC/GRM225

0805

10

mF/6.3 V

+80%/−20%

30 m

W

VISHAY

Tantalum/594C/593C

1206

10

mF/16 V

−

450 m

W

VISHAY

Electrolytic/94SV

1206

10

mF/10 V

−20%/+20%

400 m

W