Rainbow-electronics MAX5419 Bedienungsanleitung PDF herunterladen (Seite 11)

MAX5417/MAX5418/MAX5419

256-Tap, Nonvolatile, I

C-Interface,

Digital Potentiometers

______________________________________________________________________________________ 11

ADDRESS BYTE CONTROL BYTE DATA BYTE

12345678

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27

STOP

SCL

CYCLE

NUMBER

START

A6 A5 A4 A3 A2 A1 A0 ACK

NV V R3 R2 R1 R0 ACK D7 D6 D5 D4 D3 D2 D1 D0 ACK

VREG

0101A2A1A00 00010001 D7D6D5D4D3D2D1D0

NVREG 0101A2A1A00 00100001 D7D6D5D4D3D2D1D0

NVxVREG 0101A2A1A00 01100001 D7D6D5D4D3D2D1D0

VxNVREG 0101A2A1A00 01010001 D7D6D5D4D3D2D1D0

Table 2. Command Byte Summary

Nonvolatile Memory

The internal EEPROM consists of an 8-bit nonvolatile

device is powered down. The nonvolatile register is

programmed with the zero-scale value at the factory.

Power-Up

Upon power-up, the MAX5417/MAX5418/MAX5419

load the data stored in the nonvolatile memory register

into the volatile memory register, updating the wiper

position with the data stored in the nonvolatile memory

Standby

The MAX5417/MAX5418/MAX5419 feature a low-power

standby. When the device is not being programmed, it

goes into standby mode and power consumption is

typically 500nA.

Applications Information

The MAX5417/MAX5418/MAX5419 are intended for cir-

cuits requiring digitally controlled adjustable resis-

tance, such as LCD contrast control (where voltage

biasing adjusts the display contrast), or for programma-

ble filters with adjustable gain and/or cutoff frequency.

Positive LCD Bias Control

Figures 9 and 10 show an application where the volt-

age-divider or variable resistor is used to make an

adjustable, positive LCD bias voltage. The op amp pro-

vides buffering and gain to the resistor-divider network

made by the potentiometer (Figure 9) or to a fixed

resistor and a variable resistor (see Figure 10).

Programmable Filter

Figure 11 shows the configuration for a 1st-order pro-

grammable filter. The gain of the filter is adjusted by

R2, and the cutoff frequency is adjusted by R3. Use the

following equations to calculate the gain (G) and the

3dB cutoff frequency (f

××

23π

OUT

30V

MAX5417

MAX5418

MAX5419

OUT

30V

MAX5417

MAX5418

MAX5419

Figure 9. Positive LCD Bias Control Using a Voltage-Divider

Figure 10. Positive LCD Bias Control Using a Variable Resistor

1 2 ... 6 7 8 9 10 11 12 13 14

Kommentare zu diesen Handbüchern

Keine Kommentare

Rainbow-electronics MAX5419 Bedienungsanleitung Seite 11

Kommentare zu diesen Handbüchern

Verwandte Produkte und Handbücher für Sensoren Rainbow-electronics MAX5419