MAX1925ETC+ Maxim Integrated Products, MAX1925ETC+ Datasheet

IC CHARGER LI+ 12-TQFN

MAX1925ETC+

Manufacturer Part Number
MAX1925ETC+
Description
IC CHARGER LI+ 12-TQFN
Manufacturer
Maxim Integrated Products
Datasheet

Specifications of MAX1925ETC+

Function
Charge Management
Battery Type
Lithium-Ion (Li-Ion)
Voltage - Supply
4.5 V ~ 12 V
Operating Temperature
-40°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
12-TQFN Exposed Pad
Product
Charge Management
Operating Supply Voltage
4.25 V to 12 V
Supply Current
39 uA
Maximum Operating Temperature
+ 85 C
Minimum Operating Temperature
- 40 C
Charge Safety Timers
Yes
Mounting Style
SMD/SMT
Temperature Monitoring
Yes
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
The MAX1925/MAX1926 single-cell lithium-ion (Li+)
switch-mode battery chargers use an external PMOS
pass element step-down configuration. Charge current
is programmable, and an external capacitor sets the
maximum charge time.
Additional features include automatic input power
detection (ACON output), logic-controlled enable, and
temperature monitoring with an external thermistor. The
MAX1925 disables charging for inputs greater than
6.1V, while the MAX1926 charges for inputs between
4.25V and 12V.
The MAX1925/MAX1926 feature two precondition levels
to restore near-dead cells. The devices source 4mA to
a cell that is below 2V while sourcing C/10 to a cell
between 2V and 3V. Full charge current is then applied
above 3V. A CHG output drives an LED to indicate
charging (LED on) and fault conditions (LED blinking).
The MAX1925/MAX1926 are available in a 12-pin
4mm
the extended temperature range (-40°C to +85°C). An
evaluation kit is available to speed design.
19-2556; Rev 1; 10/02
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.
Digital Cameras
Self-Charging Battery Packs
PDAs
Cradle Chargers
4mm thin QFN package and are specified over
THRM
CHG
EN
1
2
3
________________________________________________________________ Maxim Integrated Products
ACON
12
IN
4
General Description
THIN QFN
MAX1925
MAX1926
INP
CT
11
5
Pin Configuration
EXT
CS
10
6
Applications
Switch-Mode 1-Cell Li+ Chargers
9
8
7
PGND
GND
BATT
o Small (4mm
o 4.25V to 12V Input Range (MAX1926)
o Overvoltage Lockout at 6.1V (MAX1925)
o ±0.75% Battery Regulation Voltage
o Set Charge Current with One Resistor
o Automatic Input Power Sense
o LED (or Logic-Out) Charge Status and Fault
o Programmable Safety Timer
o Autorestart at Cell = 4V
o Thermistor Monitor Input
MAX1925ETC
MAX1926ETC
Indicator
4.5V TO 12V
PART
INPUT
OFF
ON
LED
-40°C to +85°C
-40°C to +85°C
Typical Operating Circuit
CHG
CT
EN
4mm) Package
IN
RANGE
TEMP
Ordering Information
MAX1925
MAX1926
INP
ACON
EXT
PIN-
PACKAGE
12 Thin QFN
4mm
12 Thin QFN
4mm
PGND
THRM
BATT
x
x
GND
CS
4mm
4mm
Features
4.25V to 12V
INPUT
CHARGING
RANGE
4.5V to 6.1V
1-CELL
Li+
BATTERY
1

Related parts for MAX1925ETC+

MAX1925ETC+ Summary of contents

Page 1

... ACON CT CS THIN QFN ________________________________________________________________ Maxim Integrated Products 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. Switch-Mode 1-Cell Li+ Chargers o Small (4mm o 4.25V to 12V Input Range (MAX1926) o Overvoltage Lockout at 6.1V (MAX1925) o ±0.75% Battery Regulation Voltage ...

Page 2

Switch-Mode 1-Cell Li+ Chargers ABSOLUTE MAXIMUM RATINGS IN, INP, ACON to GND...........................................-0.3V to +14V CHG, EXT to PGND ...................................-0. CS, BATT, EN, THRM to GND ..................................-0. GND ................................................................-0.3V to +4V EN, THRM ...

Page 3

ELECTRICAL CHARACTERISTICS (continued CHG PGND GND INP IN unless otherwise noted. Typical values are at T PARAMETER Restart Threshold Charging restarts when BATT falls to this point If BATT exceeds ...

Page 4

Switch-Mode 1-Cell Li+ Chargers ELECTRICAL CHARACTERISTICS ( CHG PGND GND INP IN unless otherwise noted. Typical values are at T PARAMETER Supply Voltage Range V INP V INP ACON Trip point ...

Page 5

ELECTRICAL CHARACTERISTICS (continued CHG PGND GND INP IN unless otherwise noted. Typical values are at T PARAMETER CHG Output High Leakage V CHG Current ACON High Leakage V ACON ACON ...

Page 6

Switch-Mode 1-Cell Li+ Chargers (Circuit of Figure 5V, V SUPPLY BATT CHARGE-CURRENT ACCURACY vs. SUPPLY VOLTAGE BATT -10 -15 - ...

Page 7

Figure 5V, V SUPPLY BATT FREQUENCY vs. BATTERY VOLTAGE 500 V = 12V IN 450 400 350 300 250 200 150 100 50 0 2.5 3.0 3.5 ...

Page 8

Switch-Mode 1-Cell Li+ Chargers PIN NAME Charge Status LED Driver. Open-drain LED driver sinks 10mA when the MAX1925/MAX1926 are charging. CHG CHG also blinks at a 0.5Hz rate during fault states (see the Timing section). High impedance when charger is ...

Page 9

D1 POWER SOURCE C3 D3 10µF LED CHG IN 4.5V FOR MAX1926 4.25V FOR MAX1925 10mA 6.1V MAX1925 ONLY OSC C2 0.1µF ACON STATE EN MACHINE AND TIMERS TEMP FAULT 353µA 49µA THRM 10kΩ REF Figure 1. Functional Diagram _______________________________________________________________________________________ ...

Page 10

Switch-Mode 1-Cell Li+ Chargers Detailed Description The MAX1925/MAX1926 switch-mode battery chargers form a complete solution for a single-cell Li+ battery. The devices include battery undervoltage/overvoltage fault protection. The MAX1925/MAX1926 use EN and THRM for shutdown, battery detection, and temperature monitor- ...

Page 11

FULL TOPOFF 4V PREQUAL1 4mA FAULT 1V t PREQUAL2 t = t/1024 PREQUAL1 Figure 3. Charging Current and Voltage Timing Diagrams linear 4mA current source (PREQUAL1). When the cell voltage exceeds 2V, the cell ...

Page 12

Switch-Mode 1-Cell Li+ Chargers and a new battery is connected during either fast-charge or full topoff modes, the charger begins with full charge current without prequalification unless the part is reset. Detect battery insertion by connecting THRM to a ther- ...

Page 13

Table 2. ACON Behavior vs. V PART V > V threshold (4.5V nom) and < 6.1V, and ACON IN V > BATT MAX1925 V > V threshold and V ACON IN (Note: This state should never occur) V ...

Page 14

Switch-Mode 1-Cell Li+ Chargers mode. To ensure stable transition from CCM to CVM choose a capacitor with the following ESR: V VHIST > × ESR SET V IHIST where V is the voltage hysteresis (15mV typ) and VHIST ...

Page 15

For the latest package outline information www.maxim-ic.com/packages.) ______________________________________________________________________________________ Switch-Mode 1-Cell Li+ Chargers Package Information PACKAGE OUTLINE 12,16,20,24L QFN THIN, 4x4x0.8 mm 21-0139 A 15 ...

Page 16

... 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. 16 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2002 Maxim Integrated Products ...

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