Datasheet MAX6846, MAX6847, MAX6848, MAX6849 (Maxim)

19-2947; Rev 1; 11/05
Low-Power, Adjustable Battery Monitors with Hysteresis and Integrated µP Reset MAX6846–MAX6849 General Description Features
The MAX6846–MAX6849 are a family of ultra-low-power ♦
User-Adjustable Thresholds for Monitoring
battery monitors with integrated microprocessor (µP)
Single-Cell Li+ or Multicell Alkaline/NiCd/NiMH
supervisors. The user-adjustable battery monitors are
Applications
offered with single or dual low-battery output options that can be used to signal when the battery is OK (enabling ♦
Single and Dual Low-Battery Output Options
full system operation), when the battery is low (for low- ♦
Independent µP Reset with Manual Reset
power system operation), and when the battery is dead (to disable system operation). These devices also have ♦
Factory-Set Reset Thresholds for Monitoring 1.8V
an independent µP supervisor that monitors VCC and
to 3.3V Systems
provides an active-low reset output. A manual reset ♦
Available with 150ms (min) or 1.2s (min) V
function is available to reset the µP with a pushbutton.
CC Reset Timeout Period Options
The MAX6846–MAX6849 are ideal for single-cell lithium- ion (Li+) or multicell alkaline/NiCd/NiMH applications. ♦
150ms (min)
LBO
Timeout Period
When the battery voltage drops below each adjusted low ♦
Immune to Short-Battery Voltage Transients
threshold, the low-battery outputs are asserted to alert the system. When the voltage rises above the adjusted ♦
Low Current (2.5µA, typ at 3.6V)
high thresholds, the outputs are deasserted after a ♦
-40°C to +85°C Operating Temperature Range
150ms minimum timeout period, ensuring the voltages have stabilized before power circuitry is activated or pro- ♦
Small 8-Pin SOT23 Packages
viding microprocessor reset timing. These devices have user-adjustable battery threshold
Ordering Information
voltages, providing a wide hysteresis range to prevent
PART TEMP RANGE PIN-PACKAGE
chattering that can result due to battery recovery after load removal. Single low-battery outputs are supplied
MAX6846
KA_D_-T -40°C to +85°C 8 SOT23-8 by the MAX6846/MAX6847 and dual low-battery out-
MAX6847
KA_D_-T -40°C to +85°C 8 SOT23-8 puts are supplied by the MAX6848/MAX6849. All bat-
MAX6848
KA_D_-T -40°C to +85°C 8 SOT23-8 tery monitors have open-drain low-battery outputs.
MAX6849
KA_D_-T -40°C to +85°C 8 SOT23-8 The MAX6846–MAX6849 monitor system voltages
Note:
The first “_” is the V (V CC reset threshold level, suffix found CC) from 1.8V to 3.3V with seven fixed reset threshold in Table 1. The “_” after the D is a placeholder for the reset options. Each device is offered with two minimum reset timeout period suffix found in Table 2. All devices are available timeout periods of 150ms or 1200ms. The MAX6846/ in tape-and-reel only. There is a 2500 piece minimum order MAX6848 are offered with an open-drain RESET output increment for standard versions (see Standard Versions table). and the MAX6847/MAX6849 are offered with a push- Sample stock is typically held on standard versions only. Non- pull RESET output. standard versions require a minimum order increment of 10,000 pieces. Contact factory for availability. The MAX6846–MAX6849 are offered in a SOT23 pack- Devices are available in both leaded and lead-free packaging. age and are fully specified over a -40°C to +85°C temp- Specify lead-free by replacing “-T” with “+T” when ordering. erature range.
Applications Pin Configurations
Battery-Powered Systems (Single-Cell Li+ or Multicell NiMH, NiCd, Alkaline) TOP VIEW Cell Phones/Cordless Phones Portable Medical Devices VDD 1 8 VCC VDD 1 8 VCC Digital Cameras GND 2 7 HTHIN GND 2 7 HTHIN MAX6846 MAX6848 Pagers LTHIN 3 MAX6847 6 MR LTHIN 3 MAX6849 6 LBOH PDAs LBO 4 5 RESET LBOL 4 5 RESET MP3 Players Electronic Toys
SOT23 SOT23 ________________________________________________________________ Maxim Integrated Products 1 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.