Rainbow Electronics MAX6652 User Manual

General Description

The MAX6652 system supervisor monitors multiple
power-supply voltages, including its own, and also fea­tures an on-board temperature sensor. Voltages and
temperature are converted to an 8-bit code using an
analog-to-digital converter (ADC). A multiplexer automat­ically sequences through the voltage and temperature
measurements. The digitized signals are then stored in
registers and compared to the over/under threshold lim­its programmed over the 2-wire serial interface.

When a temperature measurement exceeds the pro­grammed threshold, or when an input voltage falls out­side the programmed voltage limits, the MAX6652
generates a latched interrupt output ALERT. Three inter­rupt modes are available for temperature excursions:
default mode, one-time interrupt mode, and comparator
mode. The ALERT output is cleared, except for tempera­ture interrupts generated in comparator mode, by read­ing the interrupt status register (Table 5). The ALERT
output can also be masked by writing to the appropriate
bits in the interrupt mask register (Table 6) or by setting
bit 1 of the configuration register (Table 4) to 0. The
MAX6652 I2C™-compatible/SMBus interface also
responds to the SMB alert response address.

The 2-wire serial interface accepts both I2C and standard
system management bus (SMBus) write byte, read byte,
send byte, and receive byte commands to program the
alarm thresholds and to read voltage and temperature
data. Voltage data is scaled so that when the nominal
voltage is present at a pin (e.g., 3.3V for the 3.3VINpin),
the conversion result is equal to 3/4 of the ADC full-scale
range or a decimal count of 192 (Table 3). The tempera­ture data format is 7 bits plus sign, with each data bit
representing 1°C, in two's complement format (Table 2).

The MAX6652 has only one address pin, ADD. One of
four different address codes can be selected by con­necting the ADD pin to GND, VCC, SDA, or SCL.
Whenever an I2C-compatible/SMBus transaction is initiat­ed, the two LSBs of the slave address register are deter­mined by connection, setting the chip address to one of
four possible values. In addition, an address code can
also be directly written to the serial address register. This
code will overwrite the code set by connection of the
ADD pin, until the MAX6652 is taken through a power-on
reset cycle.

The MAX6652 features 60Hz or 50Hz line-frequency
rejection for optimal performance. The device operates
from +2.7V to +5.5V and is specified for operation from

-40°C to +125°C. It is available in a tiny 10-pin µMAX
package.

Features

♦ Monitors Four Voltages (2.5V, 3.3V, 12V, VCC)

♦ Monitors Local Temperature

♦ Temperature Measurement Accuracy,

±2°C (T

A

= +25°C)

♦ User-Programmable Voltage and Temperature

Thresholds

♦ Alert Function with Ability to Respond to SMB

Alert Response Address

♦ +2.7V to +5.5V Supply Range

♦ -40°C to +125°C Temperature Range

♦ 60Hz or 50Hz Line-Frequency Rejection

♦ Tiny 10-Pin µMAX Package

Applications

MAX6652

Temperature Sensor and System Monitor

in a 10-Pin µMAX

________________________________________________________________ Maxim Integrated Products 1

Pin Configuration

19-1959; Rev 1; 8/01

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Ordering Information

I2C is a trademark of Philips Corp.

Workstations

Servers

Networking

Telecommunications

Typical Application Circuit and Functional Diagram appear
at end of data sheet.

PART TEMP. RANGE PIN-PACKAGE

MAX6652AUB -40°C to +125°C 10 µMAX

TOP VIEW

1

12V

IN

2

2.5V

IN

3.3V

IN

GND ALERT

MAX6652

3

4

5

MAX

µ

10

V

CC

9

SCL

8

SDA

7

ADDN.C.

6

MAX6652

Temperature Sensor and System Monitor
in a 10-Pin µMAX

2 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS

(TA= -40°C to +125°C, unless otherwise noted. Typical values are at VCC= +5V, TA= +25°C.)

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

VCC........................................................................-0.3V to +6.0V

Voltage on 12V

IN

...................................................-0.3V to +16V

All Other Pins ........................................................-0.3V to +6.0V

Output Current (SDA, ALERT) ............................-1mA to +50mA

Junction Temperature .....................................................+150°C

Operating Temperature Range ........................-40°C to +125°C

Storage Temperature Range ............................-65°C to +150°C

Continuous Power Dissipation (T

A

= +70°C)

10-Pin µMAX (derate 5.6mW/°C above +70°C) ..........444mW

Lead Temperature (soldering, 10s) ................................+300°C

ABSOLUTE MAXIMUM RATINGS

All Voltages Are Referenced to GND

POWER SUPPLY

Supply Voltage V

Supply Current

Power-On Reset Voltage VCC_ rising or falling edge 2 V

TEMPERATURE

PSRR VCC = +2.7V to +5.5V 0.7 1.3 °C/V

Resolution ±1 °C

ADC CHARACTERISTICS

Total Unadjusted Error TUE VIN > 10LSB ±1 ±1.5 %

Differential Nonlinearity DNL VIN > 10LSB ±1 LSB

Supply Sensitivity PSS VCC = +2.7V to +5.5V ±1 V

Input Resistance R

Total Monitoring Cycle Time tc (Note 1) 200 300 ms

SCL, SDA, ADD

Logic Input Low Voltage V

Logic Input High Voltage V

SDA Output Low Voltage V

Input Leakage Current I

ALERT

Output Low Voltage V

TIMING

Serial Clock Frequency f

Bus Free Time Between STOP and
START

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

CC

I

I

LEAK

SCL

t

BUF

Active 200 500 µA

CC

Shutdown mode, all digital inputs are

SD

grounded

12VIN, 2.5VIN, 3.3V

IN

IL

VCC≤ 3.6V 2.0 V

IH

VCC > 3.6V 2.6 V

I

OL

OLA

= 3mA 400 mV

SINK

VIN = 0 or 5V ±1 µA

I

= 1.2mA, VCC > 2.7V 0.3 V

SINK

I

= 3.2mA, VCC > 4.5V 0.4 V

SINK

TA= +25°C ±2

-20°C ≤ TA≤ +80°C ±3 °CAccuracy (Note 5) VCC = +5V

-40°C ≤ T

IN

≤ +125°C ±5

A

2.7 5.5 V

<1 10 µA

100 150 200 kΩ

0.8 V

0 400 kHz

1.3 µs

MAX6652

Temperature Sensor and System Monitor

in a 10-Pin µMAX

_______________________________________________________________________________________ 3

Note 1: Total monitoring time includes temperature conversion and four analog input voltage conversions.
Note 2: A master device must provide at least a 300ns hold time for the SDA signal, referred to V

IL

of the SCL signal, to bridge the

undefined region of SCL’s falling edge.

Note 3: C

B

= total capacitance of one bus line in pF. Rise and fall times are measured between 0.3 x VCCto 0.7 x VCC.

Note 4: Input filters on SDA, SCL, and ADD suppress noise spikes <50ns.
Note 5: Guaranteed but not tested over the entire temperature range.

ELECTRICAL CHARACTERISTICS (continued)

(TA= -40°C to +125°C, unless otherwise noted. Typical values are at VCC= +5V, TA= +25°C.)

Typical Operating Characteristics

(VCC= +5V, ADD = GND, ALERT = 10kΩto VCC, TA= +25°C, unless otherwise noted.)

0

100

50

200

150

250

300

2.5 3.5 4.03.0 4.5 5.0 5.5

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX6652 toc01

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (µA)

A

B
C

D
E

A: TA = +125°C
B: T

A

= +85°C

C: T

A

= +25°C

D: T

A

= 0°C

E: T

A

= -40°C

250

225

200

175

150

1 1000

SUPPLY CURRENT

vs. SCL CLOCK FREQUENCY

MAX6652 toc02

CLOCK FREQUENCY (kHz)

SUPPLY CURRENT (µA)

VCC = +5V
SCL = 0 to +5V

-5

-2

-3

-4

-1

0

1

2

3

4

5

2.5 3.53.0 4.0 4.5 5.0 5.5

TEMPERATURE ERROR

vs. SUPPLY VOLTAGE

MAX6652 toc03

SUPPLY VOLTAGE (V)

TEMPERATURE ERROR (°C)

TA = +85°C

TA = 0°C

TA = -40°C

START Condition Hold Time t

STOP Condition Hold Time t

Clock Low Period t

Clock High Period t

Data Setup Time t

Data Hold Time t

Receive SCL/SDA Minimum
Rise Time

Receive SCL/SDA Maximum
Rise Time

Receive SCL/SDA Minimum
Fall Time

Receive SCL/SDA Maximum
Fall Time

Transmit SDA Fall Time t

Pulse Width of Spike
Suppressed

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

HD:STA

SU:STO

LOW

HIGH

SP:DAT

HD:DAT

t

t

t

t

t

SP

(Note 2) 0 0.9 µs

(Note 3)

R

(Note 3) 300 ns

R

(Note 3)

F

(Note 3) 300 ns

F

400pF, I

F

SINK

= 3mA

(Note 4) 50 ns

0.6 µs

0.6 µs

1.3 µs

0.6 µs

100 ns

20 +

0.1C

B

20 +

0.1C

B

20 +

0.1C

B

300 ns

ns

ns

MAX6652

Temperature Sensor and System Monitor
in a 10-Pin µMAX

4 _______________________________________________________________________________________

Typical Operating Characteristics (continued)

(VCC= +5V, ADD = GND, ALERT = 10kΩto VCC, TA= +25°C, unless otherwise noted.)

1k 10k

-10

-8

-6

-2

-4

0

2

1 10 100

TEMPERATURE ERROR

vs. SUPPLY NOISE FREQUENCY

MAX6652 toc04

SUPPLY NOISE FREQUENCY (kHz)

TEMPERATURE ERROR (°C)

-9

-7

-3

-5

-1

1

200mVp-p

VCC = +5V

BYPASS CAP REMOVED

TEMPERATURE ERROR

vs. TEMPERATURE

MAX6652 toc05

-1.00

-0.75

-0.25

-0.50

0.50

0.75

0.25

0

1.00

TEMPERATURE ERROR (°C)

-50 0 25-25

50

75 100 125

TEMPERATURE (°C)

Pin Description

PIN NAME FUNCTION

1 12V

2 2.5V

3 3.3V

4 N.C. No Connection. Can be connected to GND to improve thermal conductivity.

5 GND Ground

6 ALERT

7 ADD

8 SDA I2C-Compatible/SMBus Serial Data Interface

9 SCL I2C-Compatible/SMBus Serial Clock Input

10 V

CC

Analog Input. Monitors 12V supply.

IN

Analog Input. Monitors 2.5V supply.

IN

Analog Input. Monitors 3.3V supply.

IN

SMBus Alert (Interrupt) Output, Open Drain. Alerts the master that a temperature or voltage limit
has been violated.

SMBus Address Select Input. ADD is sampled at the beginning of each I

2

C-compatible/SMBus
transaction, and the 2 LSBs of the slave address register are detemined by ADD's connection to
GND, SDA, SCL, or V

CC

.

Supply Voltage Input, +2.7V to +5.5V. Also serves as a voltage monitor input. Bypass VCC to GND
with a 0.1µF capacitor.