Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsPMIC - system monitor Reset/power-on reset SOT 143 4

General Description

The MAX6314 low-power CMOS microprocessor (µP)

supervisory circuit is designed to monitor power

supplies in µP and digital systems. The MAX6314’s

RESET output is bidirectional, allowing it to be directly

connected to µPs with bidirectional reset inputs, such

as the 68HC11. It provides excellent circuit reliability

and low cost by eliminating external components and

adjustments. The MAX6314 also provides a debounced

manual reset input.

This device performs a single function: it asserts a reset

signal whenever the V

supply voltage falls below a

preset threshold or whenever manual reset is asserted.

Reset remains asserted for an internally programmed

interval (reset timeout period) after V

has risen above

the reset threshold or manual reset is deasserted.

The MAX6314 comes with factory-trimmed reset

threshold voltages in 100mV increments from 2.5V

to 5V. Preset timeout periods of 1ms, 20ms, 140ms,

and 1120ms (minimum) are also available. The device

comes in a SOT143 package.

For a µP supervisor with an open-drain reset pin, see

the MAX6315 data sheet.

________________________Applications

Computers

Controllers

Intelligent Instruments

Critical µP and µC Power Monitoring

Portable/Battery-Powered Equipment

Features

♦ Small SOT143 Package

♦ RESET Output Simplifies Interface to

Bidirectional Reset I/Os

♦ Precision Factory-Set V

Reset Thresholds:

100mV Increments from 2.5V to 5V

♦ ±1.8% Reset Threshold Accuracy at T

= +25°C

♦ ±2.5% Reset Threshold Accuracy Over Temp.

♦ Four Reset Timeout Periods Available:

1ms, 20ms, 140ms, or 1120ms (minimum)

♦ Immune to Short V

Transients

♦ 5µA Supply Current

♦ Pin-Compatible with MAX811

MAX6314

68HC11/Bidirectional-Compatible

µP Reset Circuit

________________________________________________________________ Maxim Integrated Products 1

MRRESET

GND

MAX6314

SOT143

TOP VIEW

Pin Configuration

MAX6314

GND

RESET

µP

RESET

LASER-

TRIMMED

RESISTORS

4.7kΩ

68HC11**

**OR OTHER µC/µP WITH BIDIRECTIONAL RESET I/O PIN.

RESET

CIRCUITRY

Typical Operating Circuit

19-1090; Rev 2; 12/05

Ordering Information continued at end of data sheet.

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

PART

†

NOMINAL

(V)

MIN t

(ms)

TOP

MARK

††

MAX6314US50D1-T 5.00 1 AA_ _

MAX6314US49D1-T 4.90 1 AB_ _

MAX6314US48D1-T 4.80 1 AC_ _

MAX6314US47D1-T 4.70 1 AD_ _

MAX6314US46D1-T 4.63 1 AE_ _

MAX6314US45D1-T 4.50 1 AF_ _

†

The MAX6314 is available in a SOT143 package, -40°C to

+85°C temperature range.

††

The first two letters in the package top mark identify the part,

while the remaining two letters are the lot tracking code.

Devices are available in both leaded and lead-free packaging.

Specify lead-free by replacing “-T” with “+T” when ordering.

Summary of content (8 pages)

PAGE 1
9-1090; Rev 2; 12/05 68HC11/Bidirectional-Compatible µP Reset Circuit The MAX6314 low-power CMOS microprocessor (µP) supervisory circuit is designed to monitor power supplies in µP and digital systems. The MAX6314’s RESET output is bidirectional, allowing it to be directly connected to µPs with bidirectional reset inputs, such as the 68HC11. It provides excellent circuit reliability and low cost by eliminating external components and adjustments. The MAX6314 also provides a debounced manual reset input.
PAGE 2
MAX6314 68HC11/Bidirectional-Compatible µP Reset Circuit ABSOLUTE MAXIMUM RATINGS VCC ........................................................................-0.3V to +6.0V All Other Pins..............................................-0.3V to (VCC + 0.3V) Input Current (VCC) .............................................................20mA Output Current (RESET)......................................................20mA Rate of Rise (VCC) ...........................................................
PAGE 3
68HC11/Bidirectional-Compatible µP Reset Circuit SUPPLY CURRENT vs. TEMPERATURE PULLUP CHARACTERISTICS MAX6314-01 MAX6314-02 6 +5V 4.7kΩ 74HC05 5 MAX6314 PULL-UP 2V/div +5V 74HC05 VCC RESET 100pF SUPPLY CURRENT (µA) 4.7kΩ PULL-UP 2V/div 100pF MAX6314 MR INPUT 5V/div GND VCC = 5V 4 3 VCC = 3V 2 VCC = 1V 1 0 -50 200ns/div -30 -10 30 10 50 90 70 TEMPERATURE (°C) TA = +25°C 2 TA = -40°C 1 40 VTH = 4.63V 30 VTH = 3.00V 20 10 2 3 -50 5 4 -30 -10 10 30 50 1.004 1.002 1.
PAGE 4
MAX6314 68HC11/Bidirectional-Compatible µP Reset Circuit ______________________________________________________________Pin Description PIN NAME 1 GND FUNCTION 2 RESET Active-Low Complementary Output. In addition to the normal n-channel pulldown, RESET has a p-channel pullup transistor in parallel with a 4.7kΩ resistor to facilitate connection to µPs with bidirectional resets. See the Reset Output section. 3 MR Manual Reset Input. A logic low on MR asserts reset.
PAGE 5
68HC11/Bidirectional-Compatible µP Reset Circuit The MAX6314 has a reset output consisting of a 4.7kΩ pull-up resistor in parallel with a P-channel transistor and an N-channel pull down (Figure 1), allowing this IC to directly interface with microprocessors (µPs) that have bidirectional reset pins (see the Reset Output section). Reset Output A µP’s reset input starts the µP in a known state. The MAX6314 asserts reset to prevent code-execution errors during power-up, power-down, or brownout conditions.
PAGE 6
MAX6314 68HC11/Bidirectional-Compatible µP Reset Circuit VCC VCC 68HC11 4.7kΩ MR RESET RESET CIRCUITRY CIN RESET RESET CIRCUITRY CIN CSTRAY MAX6314 RESET CIN OTHER DEVICES Figure 2. MAX6314 Supports Additional Devices on the Reset Bus MR has an internal 63kΩ pullup resistor, so it can be left open if not used. Connect a normally open momentary switch from MR to GND to create a manual reset function; external debounce circuitry is not required.
PAGE 7
68HC11/Bidirectional-Compatible µP Reset Circuit MAX6314 VCC tRP OR µC RESET DELAY RESET 0.5V tS RESET PULLED LOW BY µC OR RESET GENERATOR 0.8 x VCC tR ACTIVE PULL-UP TURNS ON Figure 4. RESET Timing Diagram ___________________________________________Ordering Information (continued) NOMINAL VTH (V) PART† MIN tRP (ms) TOP MARK†† PART† NOMINAL VTH (V) MIN tRP (ms) TOP MARK†† MAX6314US44D1-T††† 4.39 1 AG_ _ MAX6314US25D1-T 2.50 1 CN_ _ MAX6314US43D1-T 4.30 1 AH_ _ MAX6314US50D2-T 5.
PAGE 8
MAX6314 68HC11/Bidirectional-Compatible µP Reset Circuit _____________________________Ordering and Marking Information (continued) NOMINAL VTH (V) MIN tRP (ms) TOP MARK†† MAX6314US32D2-T 3.20 20 DK_ _ MAX6314US31D2-T 3.08 20 DL_ _ MAX6314US30D2-T 3.00 20 DM_ _ MAX6314US26D3-T††† 2.63 140 EV_ _ MAX6314US29D2-T 2.93 20 DN_ _ MAX6314US25D3-T 2.50 140 EW_ _ MAX6314US28D2-T 2.80 20 DO_ _ MAX6314US50D4-T 5.00 1120 EX_ _ PART† NOMINAL VTH (V) MIN tRP (ms) MAX6314US28D3-T 2.