MICREL MIC2776L-BM5, MIC2776N-BM5, MIC2776H-BM5 Datasheet

MIC2776 Micrel

MIC2776

Micro-Power Low Voltage Supervisor

Advance Information

General Description

The MIC2776 is a power supply supervisor which provides
under-voltage monitoring and power-on reset generation in a
compact 5-pin SOT package. Features include an adjustable
under-voltage detector, a delay-generator, a manual reset
input, and a choice of active-high, active-low, or open-drain
active-low reset output. The user-adjustable monitoring input
is compared against a 300mV reference. This low reference
voltage allows monitoring voltages lower than those sup­ported by previous supervisor ICs.

The reset output is asserted for no less than 140ms at power­on and any time the input voltage drops below the reference
voltage. It remains asserted for the timeout period after the
input voltage subsequently rises back above the threshold
boundary. A reset can be generated at any time by asserting
the manual reset input, /MR. The reset output will remain
active at least 140ms after the release of /MR. The /MR input
can also be used to daisy-chain the MIC2776 onto existing
power monitoring circuitry or other supervisors. Hysteresis is
included to prevent chattering due to noise. Typical supply
current is a low 3.0µA.

Ordering Information

Features

• User-adjustable input can monitor supplies as low as

0.3V

• ±1.5% threshold accuracy

• Separate VDD input

• Generates power-on reset pulse (140ms min.)

• Manual reset input

• Choice of active-high, active-low or open-drain active­low reset output

• Inputs can be pulled above VDD (7V abs. max.)

• Open-drain output can be pulled above VDD (7V abs.
max.)

• Ultra-low supply current, 3.0µA typical

• Rejects brief input transients

• IttyBitty™ SOT-23-5 package

Applications

• Monitoring processor, ASIC, or FPGA core voltage

• Computer systems

• PDAs/Hand-held PCs

• Embedded controllers

• Telecommunications systems

• Power supplies

• Wireless / cellular systems

• Networking hardware

Part Number Marking Reset Output Temperature Range Package

MIC2776N-BM5 UKAA Open-Drain, Active-Low /RST –40°C to +85°C SOT-23-5

MIC2776H-BM5 ULAA Active-High, Complementary RST –40°C to +85°C SOT-23-5

MIC2776L-BM5 UMAA Active-Low, Complementary /RST –40°C to +85°C SOT-23-5

Typical Application

V

1.0V

CORE

V

2.5V

I/O

R1

R2

Power_Good

Manual
Reset

IttyBitty™ is a trademark of Micrel, Inc.

Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 [phone] • fax + 1 [phone] • http://www.micrel.com

MIC2776L

/RST

VDD
IN

/MR GND

September 29, 2000 1 MIC2776

MICROPROCESSOR

VCORE

VI/O

/RESET

GND

MIC2776 Micrel

Pin Configuration

GND

2

RST

VDDIN

GND

2

/RST

13

VDDIN

13

/MR

45

SOT-23-5 (M5)

“L” and “N” Version

/MR

45

SOT-23-5 (M5)

“H” Version

Pin Description

Pin Number Pin Number Pin Name Pin Function

MIC2776H MIC2776L

MIC2776N

1 RST Digital (Output): Asserted high whenever V

voltage. It will remain asserted for no less than 140ms after V
above the threshold limit.

1 /RST Digital (Output): Asserted low whenever V

voltage. It will remain asserted for no less than 140ms after V
above the threshold limit. (open-drain for “N” version)

2 2 GND Ground

3 3 /MR Digital (Input): Driving this pin low initiates an immediate and unconditional

reset. Assuming IN is above the threshold when /MR is released (returns
high), the reset output will be de-asserted no less than 140ms later. /MR
may be driven by a logic signal or a mechanical switch. /MR has an internal
pull-up to VDD and may be left open if unused.

4 4 IN Analog (Input): The voltage on this pin is compared to the internal 300mV

reference. An under-voltage condition will trigger a reset sequence.

5 5 VDD Analog (Input): Independent supply input for internal circuitry.

falls below the reference

IN

falls below the reference

IN

returns

IN

returns

IN

MIC2776 2 September 29, 2000

MIC2776 Micrel

Absolute Maximum Ratings (Note 1)

Supply Voltage (V
Input Voltages (V

RST, (/RST) Current .................................................. 20mA

Storage Temperature (T

ESD Rating, Note 3 ................................................... 1.5kV

) ..................................... –0.3V to +7V

DD

, V

IN

) .............................. –0.3V to +7V

/MR

) ....................... –65°C to +150°C

S

Operating Ratings (Note 2)

Supply Voltage (V
Input Voltages (V
Output Voltages

V

(N version) ..................................... –0.3V to +6.0V

/RST

V

, V

/RST

RST

) .................................. +1.5V to +5.5V

DD

, V

IN

) ........................... –0.3V to +6.0V

/MR

(H and L versions) ....... –0.3V to V

DD

+ 0.3V

Ambient Temperature Range (TA) ............. –40°C to +85°C

Electrical Characteristics

Package Thermal Resistance (θ

VDD = 3.3V; TA = +25°C, bold values indicate –40°C ≤ TA ≤ +85°C; unless noted

Symbol Parameter Condition Min Typ Max Units

I

DD

IN, UNDER-VOLTAGE DETECTOR INPUT

V

REF

V

HYST

I

IN

RESET OUTPUTS (/RST, RST)

t

PROP

t

RST

V

OL

V

OH

MANUAL RESET INPUTS (/MR)

V

IH

V

IL

t

PROP

t

MIN

I

PU

I

IN

Note 1. Exceeding the absolute maximum rating may damage the device.

Note 2. The device is not guaranteed to function outside its operating rating.

Note 3. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5k in series with 100pF.

Note 4. VDD operating range is 1.5V to 5.5V. Output is guaranteed to be asserted down to VDD = 1.2V.

Supply Current VDD = VIN = 3.3V; /MR, RST, /RST open 3.0 µA

Under-Voltage Threshold TA = 25°C 295 300 305 mV

Hysteresis Voltage 3mv

Input Current 5pA

T

≤ TA ≤ T

MIN

Propagation Delay VIN = (V

V

= (V

IN

MAX

REF(MAX)

REF(MIN)

+ 100mV) to 20 µs
– 100mV)

Reset Pulse Width 140 280 ms

RST or /RST Output Voltage Low I

RST or /RST Output Voltage High I

= 1.6mA; 0.3 V

SINK

VDD ≥ 1.6V

= 100µA; 0.3 V

I

SINK

VDD ≥ 1.2V, Note 4

SOURCE

= 500µA; 0.8V

VDD ≥ 1.5V

(H and L Version Only) I

SOURCE

= 10µA; 0.8V

VDD ≥ 1.2V, Note 4

Input High Voltage 1.5V ≤ VDD ≤ 5.5V 0.7V

Input Low Voltage 1.5V ≤ VDD ≤ 5.5V 0.3V

Propagation Delay V

Minimum Input Pulse Width Reset Occurs, V

/MR

< V

IL

< V

/MR

IL

Internal Pull-Up Current 100 nA

Input Current, /MR V

/MR

< V

IL

) ...................... 256°C/W

JA

10 nA

DD

DD

DD

DD

5 µs

33 ns

100 nA

V

V

V

V

September 29, 2000 3 MIC2776