e017015.PDF

(44 KB) Pobierz

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">

Step-Up/Step-Down

Switching Regulator

015

If you wish to convert a range of possible input voltages

into an output voltage that lies somewhere in the middle of

that range, a regulator that can automatically switch

between step-up and step-down modes is required. Such

a device is the MAX1759 from Maxim ( www.maxim-ic.com ) ,

which can take in an input voltage between +1.6 V and

+5.5 V and generate an output between +2.5 V and +5.5 V.

It is based around a switched capacitor (C2).

A further special feature of the MAX1759 is the automatic

detection of the potential divider R3/R4. This allows it to

30

Elektor Electronics

7-8/2001

855736223.088.png

855736223.099.png

855736223.110.png

855736223.121.png

855736223.001.png

855736223.012.png

855736223.023.png

855736223.034.png

855736223.042.png

855736223.043.png

855736223.044.png

855736223.045.png

855736223.046.png

855736223.047.png

855736223.048.png

855736223.049.png

855736223.050.png

855736223.051.png

855736223.052.png

855736223.053.png

855736223.054.png

855736223.055.png

855736223.056.png

855736223.057.png

855736223.058.png

855736223.059.png

855736223.060.png

855736223.061.png

855736223.062.png

855736223.063.png

855736223.064.png

855736223.065.png

855736223.066.png

855736223.067.png

SUMMER CIRCUITS COLLECTION

C2

C2

0µ33

0µ33

V OUT

7

8

7

8

+3V3

+1V6...+5V5

+1V6...+5V5

+2V5...+5V5

CXN

CXP

CXN

CXP

100mA max.

3

9

3

9

IN

OUT

IN

OUT

R3

C1

C3

C1

C3

IC1

IC1

R2

R2

4

4

R1

R1

10µ

16V

10µ

16V

10µ

16V

10µ

16V

MAX1759

MAX1759

10

10

FB

FB

GND

+3V3

GND

+3V3

2

1

2

1

SHDN

POK

SHDN

POK

R4

SHUTDOWN

POWER OK

SHUTDOWN

POWER OK

GND

PGND

GND

PGND

5

6

5

6

014109 - 11

014109 - 12

produce an externally settable output voltage between

+2.5 V and +5.5 V, as given by the following formula:

V OUT = 1.235 V (1 + R3/R4)

switches over to an internal voltage reference giving a

fixed output voltage of 3.3 V.

The open-drain ‘power OK’ output POK goes low when

the regulator control loop is not stabilised, and is pulled

high when the output voltage is stable and at the desired

value.

The resistors should be chosen with values of the order of

100 k

.

If the feedback input FB is tied to ground, the MAX1759

(014109-1)

855736223.068.png

855736223.069.png

855736223.070.png

855736223.071.png

855736223.072.png

855736223.073.png

855736223.074.png

855736223.075.png

855736223.076.png

855736223.077.png

855736223.078.png

855736223.079.png

855736223.080.png

855736223.081.png

855736223.082.png

855736223.083.png

855736223.084.png

855736223.085.png

855736223.086.png

855736223.087.png

855736223.089.png

855736223.090.png

855736223.091.png

855736223.092.png

855736223.093.png

855736223.094.png

855736223.095.png

855736223.096.png

855736223.097.png

855736223.098.png

855736223.100.png

855736223.101.png

855736223.102.png

855736223.103.png

855736223.104.png

855736223.105.png

855736223.106.png

855736223.107.png

855736223.108.png

855736223.109.png

855736223.111.png

855736223.112.png

855736223.113.png

855736223.114.png

855736223.115.png

855736223.116.png

855736223.117.png

855736223.118.png

855736223.119.png

855736223.120.png

855736223.122.png

855736223.123.png

855736223.124.png

855736223.125.png

855736223.126.png

855736223.127.png

855736223.128.png

855736223.129.png

855736223.130.png

855736223.131.png

855736223.002.png

855736223.003.png

855736223.004.png

855736223.005.png

855736223.006.png

855736223.007.png

855736223.008.png

855736223.009.png

855736223.010.png

855736223.011.png

855736223.013.png

855736223.014.png

855736223.015.png

855736223.016.png

855736223.017.png

855736223.018.png

855736223.019.png

855736223.020.png

855736223.021.png

855736223.022.png

855736223.024.png

855736223.025.png

855736223.026.png

855736223.027.png

855736223.028.png

855736223.029.png

855736223.030.png

855736223.031.png

855736223.032.png

855736223.033.png

855736223.035.png

855736223.036.png

855736223.037.png

855736223.038.png

855736223.039.png

855736223.040.png

855736223.041.png

Plik z chomika:

Inne pliki z tego folderu:

bge.jpg (26 KB)
detail1.htm (5 KB)
detail2.htm (4 KB)
detail3.htm (4 KB)
detail4.htm (6 KB)

Inne foldery tego chomika:

Zgłoś jeśli naruszono regulamin