MAX9924U [MAXIM]

On-Board 5Hz/24kHz Triangle-Wave Generator;


型号：	MAX9924U
厂家：	MAXIM INTEGRATED PRODUCTS
描述：	On-Board 5Hz/24kHz Triangle-Wave Generator
文件：	总8页 (文件大小：146K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

19-4377; Rev 0; 11/08

MAX9924U Evaluation Kit

Evluates:4U/MAX925

General Description

Features

The MAX9924U evaluation kit (EV kit) is a fully assem-

bled and tested PCB that contains a differential variable

reluctance (VR) sensor interface circuit using a

♦ Demonstrates MAX9924U MODE A1, A2, B, and C

Operation

♦ Evaluates Differential and Single-Ended Sensors

MAX9924U IC in a 10-pin µMAX package. The single-

(VR or Magnetic Pickup)

channel interface circuit also features a differential

amplifier for evaluating differential or single-ended VR

sensor (magnetic pickup sensor) signal, and provides a

fixed gain of 1V/V. Input power to the EV kit circuit can

be supplied by a 4.5V to 5.5V DC source. The

MAX9924U IC temperature range is -40°C to +125°C.

♦ Demonstrates Zero-Crossing and Adaptive

Threshold Mechanism

♦ Includes Lowpass Sensor Input Filter

♦ On-Board 5Hz/24kHz Triangle-Wave Generator

♦ Evaluates MAX9925 (IC Replacement Required)

♦ Lead(Pb)-Free and RoHS Compliant

♦ Fully Assembled and Tested

The MAX9924U EV kit circuit can be configured to

demonstrate the MAX9924U IC’s operation with internal

adaptive peak threshold and zero-crossing detection

modes. It can also interface to a microcontroller PWM

signal for evaluating external thresholds. Additionally, a

configurable on-board triangle-wave generator using a

MAX9000 IC provides a 5Hz, 55Hz, 2.5kHz, or 24kHz

triangle-wave signal if no external VR signal is available

for evaluation.

Ordering Information

PART

TYPE

MAX9924UEVKIT+

EV Kit

+Denotes lead(Pb)-free and RoHS compliant.

Component List

DESIGNATION QTY

DESCRIPTION

DESIGNATION QTY

DESCRIPTION

4.7µF 20ꢀ, 25V X7R ceramic

capacitor (1206)

Murata GCM31CR71E475M

JU2, JU5

JU4

3-pin headers

C2, C7, C8

C3, C9

C4, C10

4-pin header

Not installed, 2-pin header, 0.1in

centers

JU6

0.1µF 10ꢀ, 16V X7R ceramic

capacitors (0603)

Murata GCM188R71C104K

R1, R2,

R9–R12, R20,

R21

Not installed, resistors (0805)

R1, R2, R9–R12 are open;

R20, R21 are short (PC trace)

1µF 10ꢀ, 16V X7R ceramic

capacitors (0805)

Murata GCM219R71C105K

R3, R4

1kΩ 1ꢀ resistors (0805)

4.99kΩ 1ꢀ resistors (1206)

Panasonic ERJ-8ENF4991V

0.1µF 10ꢀ, 50V X7R ceramic

capacitors (0805)

Murata GCM21BR71H104K

R5–R8

R13

R14

10kΩ 1ꢀ resistor (0805)

10kΩ 5ꢀ resistor (0805)

54.9kΩ 1ꢀ resistor (0805)

464kΩ 1ꢀ resistor (0805)

100kΩ 1ꢀ resistor (0805)

68.1kΩ 1ꢀ resistor (0805)

39.2kΩ 1ꢀ resistor (0805)

PC mini test points, yellow

1000pF 10ꢀ, 50V X7R ceramic

capacitor (0805)

Murata GCM216R71H102K

R15

R16

220pF 5ꢀ, 50V C0G ceramic

capacitor (0603)

Murata GCM1885C1H221J

R17

R18

R19

JU1, JU3,

JU7–JU10

2-pin headers

TP1, TP2

µMAX is a registered trademark of Maxim Integrated Products, Inc.

________________________________________________________________ Maxim Integrated Products

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

MAX9924U Evaluation Kit

Component List (continued)

Component Suppliers

DESIGNATION QTY

DESCRIPTION

PC mini test points, red

PC test points, black

SUPPLIER

Murata

Electronics North

America, Inc.

PHONE

WEBSITE

TP3, TP5

TP4, TP6

770-436-1300 www.murata-northamerica.com

VR sensor interface (10 µMAX)

Maxim MAX9924UAUB+

Panasonic Corp. 800-344-2112 www.panasonic.com

Note: Indicate that you are using the MAX9924U or MAX9925

when contacting these component suppliers.

High-speed op amp comparator

reference (8 SO)

Maxim MAX9000ESA+

—

Shunts (JU1–JU5, JU7–JU10)

PCB: MAX9924U Evaluation Kit+

Quick Start

Required Equipment

Before beginning, the following equipment is needed:

Detailed Description of Hardware

The MAX9924U EV kit features a differential VR sen-

sor interface circuit using a MAX9924U IC in a 10-pin

µMAX surface-mount package. The EV kit’s single-

channel interface circuit evaluates signals from both

differential and single-ended sensors. The interface

circuit provides a fixed gain of 1V/V and evaluates

•

One 5V, 100mA power supply

One voltmeter

One oscilloscope

sensor-signal amplitudes of 40mV

to 300V

with

P-P

a frequency range of 5Hz to 25kHz. Power for the EV

kit circuit can be supplied by a 4.5V to 5.5V DC

source that provides at least 100mA.

Procedure

The MAX9924U EV kit is fully assembled and tested.

Follow the steps below to verify board operation. See

Tables 1–4 for a description of the jumpers detailed in

the procedure below. Caution: Do not turn on the

power supply until all connections are completed.

The MAX9924U EV kit circuit can be configured to

demonstrate the MAX9924U MODE A1, A2, B, or C

operation. Resistors R3, R4 and capacitor C10 pro-

vide a VCC/2 source for evaluating MODE B or C. For

MODE C operation, surface-mount resistor pads (R1,

R2) are provided to configure the high- and low-

threshold voltage. Refer to the Mode Selection sec-

tion in the MAX9924/MAX9925 IC data sheet for addi-

tional information on the modes of operation.

Lowpass sensor input filtering is provided by resistors

R5, R6 on the SENSE+ input, and resistors R7, R8,

and capacitor C5 on the SENSE- input. PCB pads

provide access to the MAX9924U square-wave open-

drain output signal at COUT.

1) Connect a voltmeter to TP3 (VCC/2) and TP4 (GND)

test points.

Evluates:4U/MAX925

2) Verify that a shunt is not installed across the pins of

jumpers JU1 and JU3.

3) Verify that a shunt is installed across pins 1-2 of

jumpers JU2, JU4, and JU5 (MODE A1 operation).

4) Verify that a shunt is installed across the pins of

jumpers JU7 and JU10 and that no shunt is

installed across jumpers JU8 and JU9 (on-board

triangle-wave generator, 2.5kHz).

Additionally, PCB pads are provided for interfacing with

a user-supplied microcontroller PWM signal when eval-

uating MODE B of the MAX9924U, which enables the

MAX9924U threshold voltage to be set externally.

Resistor R13 and capacitor C4 provide a lowpass filter

for the PWM input signal connected to the FILTER PCB

pad. Refer to the Adaptive Peak Threshold section in

the MAX9924/MAX9925 IC data sheet for additional

information.

5) Connect the V_PULL PCB pad to the VCC pad to

pull the COUT signal up to VCC.

6) Connect the 5V power supply to the VCC pad.

Connect the power supply’s ground to the GND pad.

7) Turn on the power supply and verify that the volt-

meter reads approximately 2.5V.

8) Using an oscilloscope, measure the signal at the

COUT and GND pads, which should be a 2.5kHz

square waveform with amplitude of 5V.

The MAX9924U EV kit provides a configurable on-

board triangle-wave generator using a MAX9000 IC for

evaluating the MAX9924U without a sensor. Capacitors

C6, C7, resistors R15, R16, and jumpers JU8, JU9 con-

9) The EV kit circuit is ready for further evaluation using

a VR or magnetic pickup sensor. See the Jumper

Selection section for configuring the EV kit circuit.

_______________________________________________________________________________________

MAX9924U Evaluation Kit

Evluates:4U/MAX925

figure the generator frequency. The generator can be

configured for a 5Hz, 55Hz, 2.5kHz, or 24kHz triangle-

wave signal. When configured to the 5Hz signal input

mode, the EV kit circuit is used to demonstrate the

MAX9924U internal watchdog timer’s functionality.

EV kit’s triangle-wave generator (U2) or a user-supplied

sensor signal. The sensor signal is applied to the EV

kit’s SENSE+ and SENSE- PCB pads. For proper oper-

ation, the typical sensor signal should have a 40mV

P-P

to 300V

and a frequency range of 5Hz to 25kHz.

P-P

Table 1 lists the various jumper options for selecting

the signal source.

The EV kit also features test points to ease evaluating

the raw sensor input signals. Test point TP1 provides

access to the SENSE+ signal after passing through

resistors R5 and R6. TP2 provides access to the

SENSE- signal after passing through resistors R7 and

R8. Test point TP3 provides access to the VCC/2 volt-

age source, while TP4 provides access to GND.

Triangle-Wave Generator Frequency

Selection and Enable

The MAX9924U EV kit features jumpers JU8 and JU9 to

set the EV kit’s triangle-wave generator frequency. The

generator frequency is configurable to 5Hz, 55Hz,

2.5kHz, or 24kHz. Additionally, jumper JU6 is provided

to disable the generator active IC (U2) and JU10 is

used to disconnect the ramp generator signal from the

MAX9924U IN+ pin. See Table 1 for configuring JU10.

See Table 2 for the frequency selection options for

jumpers JU8 and JU9. Table 3 lists jumper JU6

enable/disable options for U2.

Jumper Selection

The MAX9924U EV kit features several jumpers to recon-

figure the interface circuit’s mode of operation, sensor

input type, and the triangle-wave generator frequency.

Sensor Signal Source (IN+, IN-)

The MAX9924U EV kit features jumpers to select the

MAX9924U IC IN+ and IN- pin signal source, either the

Table 1. Sensor Source Configuration (JU7, JU10)

JU7

JU10

MAX9924U IN+ PIN

MAX9924U IN- PIN

SENSOR SOURCE

Installed

Connected to triangle-wave generator

Connected to VCC/2

EV kit triangle-wave generator*

Connected to SENSE+ PCB pad

through resistors R5, R6

Connected to SENSE- PC pad

through resistors R7, R8

Open

External differential VR sensor

Connected to SENSE+ PCB pad

through resistors R5, R6

External single-ended VR

sensor

Installed

Connected to VCC/2

*See Table 2 for configuring the triangle-wave generator frequency.

Table 2. Triangle-Wave Generator Frequency

Configuration (JU8, JU9)

Table 3. Triangle-Wave Generator Enable

Configuration (JU6)

JU8

Installed

Open

JU9

Open

FREQUENCY

5Hz

JU6 PC TRACE

SHORT

GENERATOR

OPERATION

U2, PIN 8

Installed

Cut open

Connected to VCC

Open

Enabled

Installed

Open

55Hz

Disabled, not powered

2.5kHz

24kHz

Open

Installed

_______________________________________________________________________________________

MAX9924U Evaluation Kit

Table 4. MODE A1, A2, B, and C Configuration (JU1–JU5, JU7)

JU1

(R1, R2)

JU2

(BIAS)

JU3

(ZERO_EN)

JU4

(EXT)

JU5

(INT_THRS)

JU7

(SENSOR)

MODE

Open

1&2

2&3

1&2

Open

Installed

Open

1-2

1-3

1-4

1-2

2-3

Installed*

Open

Installed

*Open for a differential sensor or installed for singled-ended sensors or the triangle-wave generator.

MAX9924U MODE A1, A2, B, and C Operation

The MAX9924U EV kit features jumpers JU1–JU5 and

JU7 to configure the VR sensor interface circuit mode

of operation. The circuit can be configured for MODE

A1, A2, B, or C operation. Table 4 lists the various

jumper options for configuring the circuit.

MAX9924/MAX9925 IC data sheet for additional infor-

mation on selecting a mode of operation and the

Comparator section for additional information on select-

ing threshold voltages.

COUT and V_PULL

The MAX9924U open-drain comparator output is avail-

able at the COUT PCB pad. The V_PULL PCB pad is

provided to pull up the COUT signal through R14 to the

voltage connected to the V_PULL PCB pad. V_PULL

accepts voltages from 0 to 5.5V.

MODE B Operation: Supply a digital PWM signal to the

FILTER and GND pads. The signal must provide a 5V

logic-high frequency in the range of 25kHz to 100kHz.

MODE C Operation: Threshold voltage resistors R1

and R2 must be selected using the following equation.

Refer to the Comparator section and Figure 5 in the

MAX9924/MAX9925 IC data sheet for additional infor-

mation on selecting threshold voltages.

Evaluating a MAX9925

The MAX9924U EV kit can also be used to evaluate the

MAX9925 IC with externally set gain (IC replacement of

U1 required). Contact the factory to request a free sam-

ple of the MAX9925. Cut open the shorting trace across

R20 and R21 pads before populating the resistors on

these pads. To set the gain to 1V/V, install 100kΩ resis-

tors at R20 and R9 for the IN+ input and 100kΩ resis-

tors at R21 and R10 for the IN- input. Test point TP5 is

provided for probing the pin 3 signal of the MAX9925

IC during evaluation.

V_TL= [R2/(R1 + R2)] x V_BIAS

V_TH= [R1/(R1 + R2 + R14)] x (V_PULL - V_BIAS) + V_BIAS

where R2 is typically in the range of 50kΩ to 500kΩ,

R14 is 10kΩ, V_BIASis the voltage at the MAX9924U

BIAS pin, and V_PULL is the voltage connected to the

V_PULL pad. Refer to the Mode Selection section in the

Evluates:4U/MAX925

_______________________________________________________________________________________

MAX9924U Evaluation Kit

Evluates:4U/MAX925

Figure 1. MAX9924U EV Kit Schematic

_______________________________________________________________________________________

MAX9924U Evaluation Kit

Figure 2. MAX9924U EV Kit Component Placement Guide—Component Side

Evluates:4U/MAX925

_______________________________________________________________________________________

MAX9924U Evaluation Kit

Evluates:4U/MAX925

Figure 3. MAX9924U EV Kit PCB Layout—Component Side

_______________________________________________________________________________________

MAX9924U Evaluation Kit

Figure 4. MAX9924U EV Kit PCB Layout—Solder Side

Evluates:4U/MAX925

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are

implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600

is a registered trademark of Maxim Integrated Products, Inc.

MAX9924U [MAXIM]

相关型号：

MAX9924UAUB

MAX9924UAUB+

MAX9924UAUB/V

MAX9924UAUB/V+

MAX9924UEVKIT

MAX9924UEVKIT+

MAX9924_09

MAX9924_11

MAX9924_12

MAX9924_V01

MAX9925

MAX9925AUB