一,产品概述(General Description)         
      The JTMA3202 is a constant-current/constant-voltage lin-ear charger for single cell Li+ batteries. The JTMA3202needs no external MOSFETs or diodes, and accepts in-put voltages up to 6.5V. The small package and low ex-ternal component counts make the JTMA3202 an idea part
for portable applications.
      On-chip thermal regulation protects the JTMA3202 from excessive temperature and optimizes the board design for compact size and typical thermal conditions. When the junction temperature reaches the thermal regulation threshold, the charger does not shut down but simply
reduces the charge current. Charge current can be pro-grammed by connecting an external resistor from ISET pin to GND. Using an external MOSFET to disconnect the resistor from ground shuts down the charger, and re-duces the input supply current down to 25µA. The JTMA3202 also has the STAT pin to indicate charge status.
  The JTMA3202 is available in a SOT-23-5 package, and operates over the -40°C to +85°C temperature range.

二.产品特点(Features)
1.)Programmable Charge Current Up to 500mA
2.)Charge Status Output Pin
3.)Soft-Start Limits Inrush Current
4.)4.2V Charge Termination Voltage with ±1% Accuracy
5.)45mA Pre-charge Current (RSET=2K)
6.)Thermal Regulation Simplifies Board Design
7.)Enable/Disable Control
8.)Available in a SOT-23-5 Package
9.)Lead Free and Green Devices Available(RoHS Compliant)

三,应用范围 (Applications)
Bluetooth Applications
MP3 Players
Cell Phones
Wireless Appliances
四.下载产品资料PDF文档 

jtma3202

五,产品封装图 (Package)

FUNCTION
Enable in Charge Done

PIN		FUNCTION Enable in Charge Done
NO.	NAME
1
STAT	Open-Drain Charge Status Output Pin. When the battery is charging, the STAT pin is pulled low by an internal switch. In other states the STAT pin is in a high impedance state.
2	GND	Ground.
3	BATT	Charger Output Pin. Connect this pin to the positive terminal of a Li+ battery.
4	VIN	Input Supply Pin. Provides power to the charger, VIN can range from 4.35V to 6.5V and should be bypassed with a 4.7µF capacitor.
5	ISET	Charging Current Setting and Shutdown Pin. Connecting a resistor from this pin to GND to set the charge current. Disconnecting the RSET from GND allows an internal 2.5µA current to pull the ISET pin high, and when the ISET pin voltage exceeds the shutdown threshold voltage, the IC enters shutdown mode.

六.电路原理图


七,功能概述
Charge Cycle
When the JTMA3202 is powered with a battery connected,the IC firstly detects if the cell voltage is ready for full
charge current. If the battery voltage is below pre-charge threshold (2.9V typ.), the device supplies 1/10 the pro-
grammed charge current. On the contrary, when the bat-tery voltage is over the pre-charge threshold, the device
supplies the full charge current, as programmed by RSET from ISET pin to GND. When the battery voltage ap-
proaches the 4.2V termination voltage, the device enters constant-voltage mode and the full charge current gradu-
ally decreases until the charge current drops to the termi-nation current threshold, which is equal to 1/10 full charg-
ing current, and the IC stops charging (see Figure 1).
 
Full Charge Current Setting
The full charge current is programmed by connecting a resistor from the ISET pin to ground. The full charge cur-
rent is 1000 times of the current flowing out of the ISET pin and can be calculated by the following equation:
where
VSET is ISET regulation voltage (1V, typical).KSET is the charging current set factor (1000, typical).
The charging current set factor and the ISET regulation voltage are shown in the Electrical Characteristics. The
ISET regulation voltage is reduced by thermal regulation function.
 
Charge Termination Detection and Recharge
Charging is terminated when ICHG falls to 10% of the full charge current set by RSET and the charger is in voltage
mode (VBATT is nearly 4.2V). The charge termination is detected by monitoring the ISET pin. When the ISET pin
voltage falls below 0.1V and takes longer than TTERM (1ms, typical), charging is terminated. The STAT output keeps
high state when the charger operates in standby mode.After charge termination, the battery voltage is monitored
by the JTMA3202 continuously. If the battery voltage drops below 4.05V and takes longer than TRECHARGE (2ms, typical),a new charge cycle starts to recharge the battery.
 
Manual Shutdown
The ISET pin provides two functions: connecting the re-sistor RSET from the ISET pin to ground to set the full
charge current; and disconnecting the RSET from GND to shut down the device. Once the RSET is disconnected, an
internal 2.5µA current pulls the ISET pin high. When the ISET pin voltage reaches the 1.21V shutdown threshold
voltage, the device enters shutdown mode. In shutdown mode, the charging stops, the VIN supply current drops
to 25µA and the battery drain current is below 1µA. Re-connecting RSET to ground enables the charger to opera-
tion normally. The STAT output keeps high state when the charger is turned to shutdown mode.
 
Thermal Regulation
The JTMA3202 is thermally regulated to keep the junction temperature at 120°C. When the junction temperature
reaches 120°C, the charger does not shut down but re-duces charge current to keep the junction temperature at
120°C. This feature protects the JTMA3202 from exces-sive temperature and allows the charger to operate with
maximum power dissipation by reudcing the charge cur-rent and optimizes the board design for compact size
and typical thermal conditions.
 
Charge Status Output (STAT)
The STAT is an open-drain output. When the charger is in charge mode, the STAT output is in pull-low state. Until
the charge current drops to the termination current threshold, the charging stops, and the STAT output is in
high impedance state.

八,相关产品

Part_No	Package & Pins	Input Voltage (V)		Quiescent Current (typ)(uA)	Charge Current (max)(A)	Battery Charge Voltage	VIN OVP	USB Input	Battery-Load Switch	Charge State Output
		min	max
JTMA3200		4.35	6	2000	1000	4.2	Y	Y	Y	Y
JTMA3201	DFN3x3-10	4.35	6	2000	1000	4.2	N	N	N	Y
JTMA3202	SOT-23-5	4.35	6	300	500	4.2	N	N	N	Y
JTMA3207	DFN3x3-10	4.35	6.5	300	500	4.2	N	N	N	Y