MC33166 查看數據表（PDF） - ON Semiconductor

零件编号

产品描述 (功能)

比赛名单

MC33166

3.0 A, Step−Up/Down/Inverting Switching Regulators

ON Semiconductor 

MC34166, MC33166

+

Oscillator

PWM

Thermal

3

ILIMIT

S

Q

R

UVLO

Vin

12 V

4

+ Cin

330

Q1

2

L

190 mH

D1

1N5822

Reference

+

+

EA

R1

1

2.4 k

5

CF

RF

C1

0.47

4.7 k R2

0.047

3.3 k

VO

−12 V/1.0 A

CO

2200

Test

Conditions

Results

Line Regulation

Load Regulation

Output Ripple

Short Circuit Current

Efficiency

Vin = 8.0 V to 24 V, IO = 1.0 A

Vin = 12 V, IO = 0.1 A to 1.0 A

Vin = 12 V, IO = 1.0 A

Vin = 12 V, RL = 0.1 W

Vin = 12 V, IO = 1.0 A

3.0 mV = ± 0.01%

4.0 mV = ± 0.017%

80 mVpp

3.74 A

81.2%

L = Coilcraft M1496−A or General Magnetics Technology GMT−0223, 42 turns of #16 AWG

on Magnetics Inc. 58350−A2 core. Heatsink = AAVID Engineering Inc. 5903B, or 5930B.

Two potential problems arise when designing the standard voltage−inverting converter with the MC34166. First, the Switch Output emitter is

limited to −1.5 V with respect to the ground pin and second, the Error Amplifier’s noninverting input is internally committed to the reference and

is not pinned out. Both of these problems are resolved by connecting the IC ground pin to the converter’s negative output as shown in Figure 23.

This keeps the emitter of Q1 positive with respect to the ground pin and has the effect of reversing the Error Amplifier inputs. Note that the voltage

drop across R1 is equal to 5.05 V when the output is in regulation.

Figure 23. Voltage−Inverting Converter

3.0″

(Bottom View)

+

+

+

− VO +

+ Vin −

+

ÎÎÎÎÎÎÎÎÎÎRFÎÎÎÎÎÎÎÎÎÎCFÎÎÎÎÎ

+

+

(Top View)

Figure 24. Voltage−Inverting Converter Printed Circuit Board and Component Layout

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