MAX1874ETE

Manufacturer Part NumberMAX1874ETE
DescriptionBattery Management Dual-Input USB/AC Adapter 1-Cell Li+
ManufacturerMaxim Integrated Products
MAX1874ETE datasheet
 


Specifications of MAX1874ETE

Battery TypeLi-Ion, Li-PolymerOperating Supply Voltage4.35 V to 6.5 V
Supply Current4 mAMaximum Operating Temperature+ 85 C
Minimum Operating Temperature- 40 CPackage / CaseTQFN-16
Charge Safety TimersNoMounting StyleSMD/SMT
Temperature MonitoringNo  
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19-2912; Rev 1; 2/07
Dual-Input, USB/AC Adapter, 1-Cell
Li+ Charger with OVP and Thermal Regulation
General Description
The MAX1874 charges a single-cell Li+ battery from
both USB and AC adapter sources. It also includes bat-
tery-to-input power switchover, so the system can be
powered directly from the power source rather than
from the battery.
In its simplest application, the MAX1874 needs no
external MOSFET or diodes, and accepts input volt-
ages up to 6.5V; however, DC input overvoltage protec-
tion up to 18V can be added with a single SOT PFET.
On-chip thermal limiting simplifies printed circuit board
(PCB) layout and allows optimum charging rate without
the thermal limits imposed by worst-case battery and
input voltage. When the MAX1874 thermal limit is
reached, the charger does not shut down but simply
reduces charging current.
Ambient or battery temperature can be monitored with
an external thermistor. When the temperature is out of
range, charging pauses.
Other features include a CHG output to indicate when
battery current tapers below a predetermined level. DC
power-OK (DCOK), USB power-OK (UOK), and power-
on (PON) outputs indicate when valid power is present.
These outputs drive logic or power-selection MOSFETs
to disconnect the charging sources from the load and
to protect the MAX1874 from overvoltage.
The MAX1874 contains no logic for communication with
the USB host. It must receive instructions from a local
microcontroller. The MAX1874 is available in a 16-pin
5mm
5mm thin QFN package and operates over the
-40°C to +85°C temperature range.
PDAs
Cell Phones
Wireless Appliances
Digital Cameras
Pin Configuration
TOP VIEW
16
15
14
13
DCLV
1
DC
2
MAX1874
CHG
3
USEL
4
5
6
7
8
THIN QFN
5mm x 5mm
________________________________________________________________ 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.
♦ Charge from USB or AC Adapter
♦ Automatic Switchover to AC Adapter
♦ Thermal Limiting Simplifies Board Design
♦ Small, High-Power 16-Pin Thin QFN Package
♦ Input Protection Up to 18V
♦ Soft-Start
♦ Automatic Battery-to-Input Load Switch
PART
MAX1874ETE
DC INPUT
Applications
USB INPUT
TO REF
12
USB
11
BYP
10
PGND
9
REF
Functional Diagram appears at the end of the data sheet.
Features
Ordering Information
PIN-
TEMP RANGE
PACKAGE
CODE
16 Thin QFN
-40°C to +85°C
T1655-2
5mm x 5mm
Typical Operating Circuit
DC
MAX1874
PON
DCOK
BATT
DCLV
UOK
USB
CHG
500mA
USEL
100mA
DCI
EN
REGULATOR
REF
THRM
NTC
THERMISTOR
GND
BYP
PGND
PKG
Li+
CELL
1

MAX1874ETE Summary of contents

  • Page 1

    ... Charge from USB or AC Adapter ♦ Automatic Switchover to AC Adapter ♦ Thermal Limiting Simplifies Board Design ♦ Small, High-Power 16-Pin Thin QFN Package ♦ Input Protection Up to 18V ♦ Soft-Start ♦ Automatic Battery-to-Input Load Switch PART MAX1874ETE DC INPUT Applications USB INPUT TO REF 12 USB 11 ...

  • Page 2

    Dual-Input, USB/AC Adapter, 1-Cell Li+ Charger with OVP and Thermal Regulation ABSOLUTE MAXIMUM RATINGS DC, DCOK to GND .................................................-0.3V to +20V DCLV, BYP, USB, UOK, DCI, REF, USEL, THRM, EN, BATT, CHG, PON to GND .............................-0.3V to +7V PGND to ...

  • Page 3

    Dual-Input, USB/AC Adapter, 1-Cell Li+ Charger with OVP and Thermal Regulation ELECTRICAL CHARACTERISTICS (continued 5V, V USB DC DCLV EN USEL noted. Typical values are +25°C.) A ...

  • Page 4

    Dual-Input, USB/AC Adapter, 1-Cell Li+ Charger with OVP and Thermal Regulation ELECTRICAL CHARACTERISTICS (continued 5V, V USB DC DCLV EN USEL noted. Typical values are +25°C.) A ...

  • Page 5

    Dual-Input, USB/AC Adapter, 1-Cell Li+ Charger with OVP and Thermal Regulation ELECTRICAL CHARACTERISTICS (continued 5V, V USB DC DCLV EN USEL noted. Typical values are +25°C.) (Note ...

  • Page 6

    Dual-Input, USB/AC Adapter, 1-Cell Li+ Charger with OVP and Thermal Regulation ( 5V, V USB DC DCLV EN BATT unless otherwise noted.) DC INPUT CURRENT vs. DC INPUT VOLTAGE ...

  • Page 7

    Li+ Charger with OVP and Thermal Regulation ( 5V, V USB DC DCLV EN unless otherwise noted.) OFF-BATTERY LEAKAGE vs. USB INPUT VOLTAGE ...

  • Page 8

    Dual-Input, USB/AC Adapter, 1-Cell Li+ Charger with OVP and Thermal Regulation PIN NAME Low-Voltage Charger Input. DCLV charges BATT through an internal MOSFET. Maximum operating 1 DCLV voltage at this pin is 6.0V. When an overvoltage protection MOSFET is connected, ...

  • Page 9

    Dual-Input, USB/AC Adapter, 1-Cell Li+ Charger with OVP and Thermal Regulation DC OVERVOLTAGE AND UNDERVOLTAGE DETECT DCOK N DCLV USB USB/DCLV DETECT UOK N DCI USEL THERMISTOR COMPARATORS _______________________________________________________________________________________ 5Ω 5Ω INPUT POWER- OK SELECT 0.25Ω 0.4Ω MAX1874 V I ...

  • Page 10

    Dual-Input, USB/AC Adapter, 1-Cell Li+ Charger with OVP and Thermal Regulation Detailed Description The MAX1874 charges a single-cell Li+ battery from either USB power sources or AC adapter sources. It contains a complete two-input linear charger that controls both battery ...

  • Page 11

    Dual-Input, USB/AC Adapter, 1-Cell Li+ Charger with OVP and Thermal Regulation acceptable range. To verify that the input voltage is stable, DCOK has an internal delay of 20ms before con- necting power to DCLV. DCOK remains operational when EN is ...

  • Page 12

    Dual-Input, USB/AC Adapter, 1-Cell Li+ Charger with OVP and Thermal Regulation The MAX1874’s thin QFN package includes a bottom metal plate that reduces thermal resistance between the die and the PCB. The external pad should be soldered to a large ...

  • Page 13

    Dual-Input, USB/AC Adapter, 1-Cell Li+ Charger with OVP and Thermal Regulation DC INPUT UP TO 6.0V C5 4.7µF 10V CERAMIC USB INPUT 6.3V CERAMIC TO REF Figure 2. A Minimal Circuit that Assumes System Load Is Only Connected to the ...

  • Page 14

    Dual-Input, USB/AC Adapter, 1-Cell Li+ Charger with OVP and Thermal Regulation OVP UP TO 18V CHARGING 500mA, FDN302 4.7µF SCHOTTKY 0.055Ω, -20V 25V CERAMIC (MBR0520L) Q1 FDN302 0.055Ω, -20V R3 10kΩ USB INPUT Figure 4. ...

  • Page 15

    Dual-Input, USB/AC Adapter, 1-Cell Li+ Charger with OVP and Thermal Regulation OVP UP TO 18V CHARGING 4.7µF FDN302 25V CERAMIC 0.055Ω, -20V 10V CERAMIC USB INPUT Figure 5. Partial-Battery Load Switching. AC adapter power is ...

  • Page 16

    Dual-Input, USB/AC Adapter, 1-Cell Li+ Charger with OVP and Thermal Regulation (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information www.maxim-ic.com/packages.) 16 ______________________________________________________________________________________ Package Information ...

  • Page 17

    ... 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. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 17 © 2007 Maxim Integrated Products Package Information (continued registered trademark of Maxim Integrated Products, Inc ...