一,产品概述(General Description)         
       The JTM8202 is a complete battery charger controller for two (8.4V) cells lithium-ion batteries.The JTM8202 provides a small, simple and efficient
solution to fast charge Li-ion battery. An external sense resistor sets the charge current with high accuracy.
       An internal resistor divider and precision reference set the final float voltage to 8.4V. When the input supply is removed, the JTM8202 automatically enters a low current sleep mode.
      The JTM8202 is available in the SOP-8L package.

二.产品特点(Features)
1.)Input Supply Range: 9V ～ 14V
2.)End-Charge-Current Detection Output
3.)Constant Switching Frequency for Minimum Noise
4.)Automatic Battery Recharge
5.)Automatic Shutdown When Input Supply is Removed
6.)Automatic Trickle Charging of Low Voltage Batteries
7.)Battery Temperature Sensing
8.)Stable with Ceramic Output Capacitor
9.)SOP-8L Package

三,应用范围 (Applications)
Charging Docks
Handheld Instruments
Portable Computers

四.下载产品资料PDF文档

jtm8202

五,产品封装图 (Package)

PIN	NAME	FUNCTION
1	VREF	Voltage Reference to Drive LED
2	VIN	Input
3	SW	Switch Output
4	GND	Ground
5	CHRG	Open-Drain Charge Status for Output
6	FB	Feedback
7	PROG	Charge Current Program
8	TS	Temperature Sense

六.电路原理图


七,功能概述
Current Regulation Phase
The JTM8202 regulates current while the battery-pack voltage is less than the regulation voltage, VO(REG).
The JTM8202 monitors charge current by the voltage drop across a sense-resistor, R3, in series with the
battery pack, and the resistor, R3, connected to the PROG pin. In order to set the current, first choose
R3 based on the regulation threshold VIREG = VPROG – VFB across this resistor. The following formula
calculates the value of the Sense resistor:
 
Battery Voltage Regulation
The voltage regulation feedback occurs through the FB pin. This input is tied to the positive side of the
battery pack. The JTM8202 monitors the battery-pack voltage between the FB and GND pins. The
JTM8202 is offered in a fixed two-cell voltage version (8.4 V).

Charge Termination Recharge
The JTM8202 monitors the charging current during the voltage-regulation phase. The JTM8202 declares a
done condition and terminates charge when the current drops to the charge termination threshold, ITERM.
A new charge cycle begins when the battery voltage falls below the VRCH threshold.
 
Battery Temperature Monitoring
 
A negative temperature coefficient (NTC) thermistor located close to the battery pack can be used to
monitor battery temperature and will not allow charging unless the battery temperature is within an
acceptable range.
 
Connect a 10kΩ thermistor from the TS pin to ground. With the 99.5µA pull-up current source, the hot
temperature voltage threshold is 479mV. For Cold temperature, the voltage threshold is set at 2.422V
with 99.5µA of pull-up current. The charge cycle begins or resumes once the temperature is within the
acceptable range.
Charge Status Indication
The JTM8202 reports the status of the charge on the CHRG pin. The following table summarized the
operation of the CHRG pin.
 
The CHRG pin can be used to drive a chip LED.
 
Low-Power Sleep Mode
 
When the input supply is disconnected, the charger automatically enters power-saving sleep mode. This
feature prevents draining the battery pack during the absence of VIN.
 
Input and Output Capacitors
 
Since the input capacitor is assumed to absorb all input switching ripple current in the converter, it must
have an adequate ripple current rating. Worst-case RMS ripple current is approximately one-half of
output charge current. Actual capacitance value is not critical. Solid tantalum capacitors have a high
ripple current rating in a relatively small surface mount package, but caution must be used when
tantalum capacitors are used for input bypass. High input surge currents can be created when the
adapter is hot-plugged to the charger and solid tantalum capacitors have a known failure mechanism
when subjected to very high turn-on surge currents. Selecting the highest possible voltage rating on the
capacitor will minimize problems. Consult with the manufacturer before use.
 
The selection of output capacitor COUT is primarily determined by ESR required to improve ripple voltage
and load transient. The output ripple ΔVOUT is approximately bounded by:

八,相关产品

2节锂电充电IC
型号	电池数量	工作模式	工作电压	最大	工作电流	恒流恒压	输出电压	开关频率	封装
				充电电流		精度
JTM8203	两节	线性，内置MOS	9V-16V	1A	0.26mA	1%	8.4V		SOP-8L
JTM8202	两节	开关式，内置MOS	9V-16V	2A	0.26mA	1%	8.4V	780KHz	SOP-8L
JTM8207	两节	开关式，外置MOS	8.9V-20V	2A	3.5mA	1%	8.4V	500KHz	SOP-8L
JTM4060	单节/两节	开关式，外置MOS	最大20V	3A		1%	4.2V/CELL	600KHz	MSOP-10
JTM4061	单节/两节	开关式，外置MOS	4.5V-12V	2A	5mA	1%	4.175V/CELL	400KHz	TSSOP-14
JTM4062	两节	开关式，外置MOS	7.5V-28V	5A	1.55mA	1%	8.4V	300KHz	TSSOP-16
多节锂电充电IC
型号	电池数量	工作模式	工作电压	最大	工作电流	恒流恒压	输出电压	开关频率	封装
				充电电流		精度
JTM4063	三节	开关式，外置MOS	7.5V-28V	5A	1.75mA	1%	12.6V	300KHz	TSSOP-16
JTM4064	四节	开关式，外置MOS	7.5V-28V	5A	1.95mA	1%	16.8V	300KHz	TSSOP-16
JTM4065	1-6节可设置	开关式，外置MOS	7.5V-28V	5A	1.7mA	1%	可调	300KHz	TSSOP-16
型号	输入电压	最大充电电流	充电类型	单节截止电压	封装形式
JTM4058	2.6-7.5V	250mA	1到8节镍镉/镍氢电池充电IC	1.35V	SOP-8
JTM4059	2.3-6.5V	1.2A	1到3节镍镉/镍氢/镍锌电池充电IC	1.35V	ESOP8
JTM4059B	3.1-6.5V	1A	1到4节镍镉/镍氢电池充电IC	1.35V	ESOP8
JTM4068	7.5-28V	扩流5A	2-17节镍氢电池充电IC	1.35V	TSSOP16
JTM4067	7.5-28V	扩流5A	单节/多节铅酸电池充电IC	3.6V	TSSOP16
型号	输入耐压	检测电压范围	检测电	输出形式	工作电流	封装	直接替代型号
			压精度
JTM61C/NXX2	12V	1.1/1.8/2.0/2.1/2.2/2.4/2.5/	2%	CMOS/N沟道	1.1uA	SOT-23	XC61FC(N)/XC61CC(N)/
		2.7/2.8/3.0/3.3/3.5/3.6/					RT9808/RT9809/AIC1680/
		3.9/4.0/4.2/4.4/5.0V					AP8822/S808/UT81XX
JTM70XX	12V	1.1/1.8/2.0/2.1/2.2/2.4/2.5/	2%	CMOS/N沟道	1.1uA	SOT-23	HT70XX/KIA70XX
		2.7/2.8/3.0/3.3/3.5/3.6/				SOT-89
		3.9/4.0/4.2/4.4/5.0V				TO-92
JTM6100	6.5V	1.2V以上，可以设置	2%	CMOS	1.8uA	SOT-25
JTM809系列	6V	2.63V/2.93V/3.08V/	1%	CMOS	1.0uA	SOT-23	MAX809/
		4.00V/4.38V/4.63V					IMP809/AME8500
JTM810系列	6V	2.63V/2.93V/3.08V/	2%	CMOS	8.0uA	SOT-23	MAX810/IMP810
		4.38V/4.63V
JTM811系列	6V	2.93V/4.00V/	2%	CMOS	8.0uA	SOT-143	MAX811/IMP811
		4.38V/4.63V
我司的JTM61C/NXXXMR/SOT-23有如下优点：
1.耐压可达12V
2.静态电流小，只有1uA(典型值).
3.输出方式有N沟道和CMOS 2种.
4.输出检测电压值范围广,从1.1V~5.0V可以定义各电压值，
可以每隔0.1V定制.
5.目前检测电压有1.1/1.8/2.0/2.2/2.4/2.5/2.7/2.8/3.0/3.3/3.5/3.6/3.9/4.0/4.2/4.4V
6.封装采用金线，全测产品，一致性好，品质稳定.
我司的JTM70XXMR/PR SOT-23/SOT-89有如下优点：
1.耐压可达12V
2.静态电流小，只有1uA(典型值).
3.输出方式是N沟道输出.
4.输出检测电压值范围广,从1.1V~5.0V可以定义各电压值，
可以每隔0.1V定制.
5.目前检测电压有1.1/1.8/2.0/2.2/2.4/2.5/2.7/2.8/3.0/3.3/3.5/3.6/3.9/4.0/4.2/4.4V
6.封装采用金线，全测产品，一致性好，品质稳定.