MIC3263 datasheet(20/32 Pages) MICREL

20 / 32 page

Micrel, Inc.

MIC3263

January 2010

M9999-012110

VIN =

OUT

12V, V

= 32V

8.2

22μH

μH

10μH

F(kH

RSLP

R LP

RSLP

400

2.24E+05

2.77 +05

2 70E+05

500

2.03E+05

2.69 +05

2 60E+05

600

1.81E+05

2.61 +05

2 51E+05

700

1.60E+05

2.53 +05

2 1E+05

800

1.39E+05

2.45 +05

2 1E+05

900

1.18E

2.37 +05

2 2E+05

+05

100

964

2.30 +05

2 2E+05

110

75231

2.22 +05

2 3E+05

120

540

2.14 +05

1 3E+05

130

327

2.06 +05

1 3E+05

1400

1.98E+05

1.74E+05

15000

1500

.64E+05

15000

1.90E+05

1600

1.82E+05

1.54E+05

15000

1700

1.74E+05

1.45E+05

15000

1800

1.66E+05

1.35E+05

15000

Table 3. RSLC Values

Boost Compensation

Current-mode control simplifies the compensation.

current mode the double pole created by the output L and

C is reduced to a single pole. The explanation for this is

beyond the scope of this data sheet, but it can be thought

because the inductor current becomes a co

sou

nstant current

rce and can’t act to change phase.

Figure 12. MIC3263 Current-Mode Loop Diagram

From the small signal block diagram the loop transfer

function is:

Figure 13. Simplified Voltage Control Loop

Equation 2

T(s) = Gea(s) × GVC(s) × H(s)

where:

CRV

OUT

H(s) =

and

⎛⎞

⎜⎟

⎝⎠

COMP

G(s) = g

Equation 3

( )

()

⎛⎞

⎜

⎟

⎠

⎛⎞

⎝

⎜⎟⎜⎟

⎞

⎛

⎝⎠⎝⎠

⎝⎠

OUT

CONTROL

OUT

G(s) =

where

⎜⎟

LOAD

D' R

D'R

OUT

LOAD

OUT

and

Ai = 20

RCS = 0.02Ω

AI and RCS are quantities that are internal to the MIC3263.

The equation for GVC(S) is a theoretical model and should

give an approximate idea of where the poles and zeros are

located.

Ri = Ai × Rcs = 0.4Ω

MIC3263 Datasheet(PDF) 20 Page - Micrel Semiconductor

MIC3263 Datasheet(HTML) 20 Page - Micrel Semiconductor

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

Datasheet Download

Link URL