View MAX1926EVKIT_990195.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

19-2594; Rev 1; 11/02
MAX1926 Evaluation Kit
General Description
The MAX1926 evaluation kit (EV kit) is a complete, fully assembled and tested, single-cell lithium-ion (Li+) battery charger. The EV kit provides a 4.2V output from input as high as 12V, and delivers up to 1A charge current. A light-emitting diode (LED) indicates the cell's charging status. The EV kit can be also used to evaluate the MAX1925, which is a single-cell Li+ battery charger with a 4.5V to 6.1V input voltage charge range. o 5V to 12V Input Voltage Range o Up to 1A Fast Charge Current o LED Charge Status and Fault Indicator o 12-Pin Thin QFN Package o Surface-Mount Construction o Fully Assembled and Tested
Features
Evaluates: MAX1925/MAX1926
Component List
DESIGNATION QTY 1 DESCRIPTION 10F 20%, 16V X5R ceramic capacitor (1210) Taiyo Yuden EMK325BJ106MN or TDK C3225X5R1C106MT 22F 20%, 6.3V tantalum capacitor (A case) AVX TAJA226M006R 0.1F 10%, 16V X7R ceramic capacitor (0603) Taiyo Yuden EMK107BJ104KA or TDK C1608X7R1C104KT or Murata GRM39X7R104K016AD Not installed, capacitor (0603) 1A, 30V Schottky diodes Nihon EP10QY03 Surface-mount LED (0805) 2-pin header Not installed, shorted by PC trace 10H, 1.3A inductor Toko A915AY-100M or Sumida CDRH5D28-100 P-channel MOSFET 3-pin SOT23 Fairchild FDN360P 0.14 1%, 1/2W sense resistor (1206) IRC LR1206-01-R140-F 100k 5% resistor (0603) Not installed, resistors (0603) 10k 5% resistor (0603) MAX1926ETC 12-pin thin QFN 4mm x 4mm, top mark AABF Shunt MAX1926 PC board PART
Ordering Information
TEMP RANGE IC PACKAGE MAX1926EVKIT 0C to +70C 12 Thin QFN 4mm x 4mm Note: To evaluate the MAX1925, request a MAX1925 free sample with the MAX1926EVKIT.
C1
C2
1
Quick Start
The MAX1926 EV kit is a fully assembled and tested surface-mount board. Follow the steps below to verify board operation. Do not turn on the power supply until all connections are completed: 1) Verify that there is a no shunt across jumper JU1 (EN). 2) Connect a voltmeter across the EV kit's BATT and GND pads. 3) Connect a 5V to 12V power supply to the VIN pad. Connect the power-supply ground to the GND pad closest to VIN. 4) Observe correct Li+ cell polarity. Connect the positive terminal of a single-cell Li+ battery to the BATT pad. Connect the negative terminal of the battery to the GND pad closest to BATT. 5) Turn on the power supply. The LED turns on if the battery voltage is below 4.2V and the charging current is above 125mA. See Table 3 for additional LED state descriptions. 6) The LED turns off once the Li+ cell has been fully charged. To evaluate the MAX1925, see the Evaluating the MAX1925 section.
C3
1
C4 D1, D2 D3 JU1 JU2 L1 Q1 R1 R2 R3, R4 R5 U1 None None
0 2 1 1 0 1 1 1 1 0 1 1 1 1
________________________________________________________________ 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.
MAX1926 Evaluation Kit Evaluates: MAX1925/MAX1926
Component Suppliers
SUPPLIER AVX Fairchild IRC Murata Nihon Sumida Taiyo Yuden TDK Toko PHONE 843-946-0238 888-522-5372 361-992-7900 770-436-1300 81-33343-3411 847-545-6700 800-348-2496 847-803-6100 847-297-0070 FAX 843-626-3123 408-882-2102 361-992-3377 770-436-3030 81-33342-5407 847-545-6720 847-925-0899 847-390-4405 847-699-1194 WEBSITE www.avxcorp.com www.fairchildsemi.com www.irctt.com www.murata.com www.niec.co.jp www.sumida.com www.t-yuden.com www.component.tdk.com www.tokoam.com
Note: Please indicate that you are using the MAX1925/MAX1926 when contacting these component suppliers.
Detailed Description
The MAX1926 EV kit is a fully assembled and tested single-cell Li+ battery charger. The EV kit contains an external P-channel MOSFET for current switching and can deliver up to 1A of current to a Li+ battery. An LED indicates the charging status of the battery. The maximum charging time is set to 3 hours with 0.1F at C3.
the resistance connected to THRM is greater than 28.69 or less than 3.967k. The MAX1926 EV kit comes with THRM connected to a 10k resistor. JU2 is not populated and is shorted by a PC trace. To connect a thermistor to the EV kit, cut open the PC trace shorting JU2. Table 2 lists JU2 functions.
LED States
The LED on the EV kit is driven by the CHG pin. Depending on the Li+ cell's charging status, the pin is low or high impedance, thus turning the LED on or off. The LED blinks at 0.5Hz when the MAX1926 enters Fault Prequal1, Fault Prequal 2, Fault Full, Fault BATT Voltage, or the Fault Temp state. For driving logic circuits, remove the LED and install a pullup resistor from a logic supply to CHG. Table 3 lists the LED states.
Jumper Selection
In the MAX1926, EN is internally pulled to 3V with an internal 300k resistance. When jumper JU1 is open, EN goes to 3V and the charger is enabled. When JU1 is shorted, EN is 0V and the charger is disabled. See Table 1 for JU1 functions In the MAX1925, EN does not have an internal pullup and must be driven high (5.5V max) or low. Extra pads (R3 and R4) are provided so that EN can be driven from a voltage-divider connected to a higher voltage without exceeding the 5.5V limit. Jumper JU2 provides options to connect THRM to a thermistor or a 10k resistor. The MAX1926 is disabled when
Evaluating the MAX1925
To evaluate the MAX1925, replace the MAX1926ETC with a MAX1925ETC. Install 100k resistors R3 and R4 to enable the IC.
Table 1. JU1 Functions
SHUNT LOCATION Installed Not installed EN PIN Connected to GND EN internally pulled to 3V MAX1926 OUTPUT MAX1926 is disabled MAX1926 is enabled
Table 2. JU2 Functions
JUMPER STATE Open Shorted (by Default) THRM PIN Connected to a thermistor using THRM pad Connect to a 10k pulldown resistor MAX1926 OUTPUT MAX1926 enabled with valid THRM resistance and EN high MAX1926 is enabled if EN is high
2
_______________________________________________________________________________________
MAX1926 Evaluation Kit Evaluates: MAX1925/MAX1926
Table 3. LED States
CHARGING STATE Off Prequal1 Prequal2 Fast Charge Full Charge Fault Prequal1 Fault Prequal2 Fault Full Fault Batt Voltage Fault Temp None CONDITION EN low, or no battery, or no wall power. Charge current = 4mA until BATT reaches 2V. Charge current = C/10 (100mA) until BATT reaches 3V. Charge current = C = 142mV/R1 (1A). Charge current has fallen to C/8 (125mA). BATT does not reach 2V before Prequal1 timeout. BATT does not reach 3V before Prequal2 timeout. Charge current does not drop to C/8 (125mA) before fullcharge timeout. Battery voltage has exceeded 4.35V. Temperature has risen above +50C or fallen below 0C if a thermistor is installed. Temp fault clears by itself. Initial power-up or enable with no battery. MAX1925: Off. MAX1926: Blinking at 0.5Hz. Blinking at rapid rate as charger cycles through Reset, Prequal1, and Done. Blinking at 0.5Hz. Clear fault by cycling input power, THRM, or EN. Off. On. On. On. Off. LED STATE
VIN
D1 C1 10F 16V R3 OPEN
S Q1
D D2
L1 10H
GND
D3 ACON
R2 100k 4
12 11 IN INP ACON U1 1 CHG CT
G 10 EXT CS 6
R4 OPEN C3 0.1F EN THRM JU2 SHORTED BY PC TRACE R5 10k
MAX1926
BATT 7
R1 0.14 1% C2 22F 6.3V
BATT
5
2 3 C4 OPEN
EN THRM
PGND
9
GND
GND
8
JU1
Figure 1. MAX1926 EV Kit Schematic
_______________________________________________________________________________________
3
MAX1926 Evaluation Kit Evaluates: MAX1925/MAX1926
Figure 2. MAX1926 EV Kit Component Placement Guide--Top Silkscreen
Figure 3. MAX1926 EV Kit PC Board Layout--Component Side
Figure 4. MAX1926 EV Kit PC Board Layout--Solder Side
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.
4 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 (c) 2002 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

▲Up To Search▲

Price & Availability of MAX1926EVKIT

	To Download MAX1926EVKIT Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .