Texas Instruments UC3909QTR, UC3909Q, UC3909N, UC3909DWTR, UC3909DW Datasheet

UC2909

UC3909

Switchmode Lead-Acid Battery Charger

FEATURES

∙Accurate and Efficient Control of Battery Charging

∙Average Current Mode Control from Trickle to Overcharge

∙Resistor Programmable Charge Currents

∙Thermistor Interface Tracks Battery Requirements Over Temperature

∙Output Status Bits Report on Four Internal Charge States

∙Undervoltage Lockout Monitors VCC and VREF

DESCRIPTION

The UC3909 family of Switchmode Lead-Acid Battery Chargers accurately controls lead acid battery charging with a highly efficient average current mode control loop. This chip combines charge state logic with average current PWM control circuitry. Charge state logic commands current or voltage control depending on the charge state. The chip includes undervoltage lockout circuitry to insure sufficient supply voltage is present before output switching starts. Additional circuit blocks include a differential current sense amplifier, a 1.5% voltage reference, a –3.9mV/°C thermistor linearization circuit, voltage and current error amplifiers, a PWM oscillator, a PWM comparator, a PWM latch, charge state decode bits, and a 100mA open collector output driver.

BLOCK DIAGRAM

UDG-95007-1

Pin numbers refer to J, N, DW packages.

1/99

UC2909

UC3909

ABSOLUTE MAXIMUM RATINGS

Supply Voltage (VCC), OUT, STAT0, STAT1 .		. . . . . . . . . . 40V
Output Current Sink . . . . . . . . . . . . . . . . .	. . . .	. . . . . . . . . 0.1A
CS+, CS- . . . . . . . . . . . . . . . . . . . . . . . . . .	-0.4 to VCC (Note 1)
Remaining Pin Voltages. . . . . . . . . . . . . . .	. . . .	. . . -0.3V to 9V
Storage Temperature . . . . . . . . . . . . . . . .	. . .	- 65°C to +150°C
Junction Temperature . . . . . . . . . . . . . . . .	. . .	- 55°C to +150°C
Lead Temperature (Soldering, 10 sec.) . . .	. . . .	. . . . . . +300°C

All currents are positive into, negative out of the specified terminal. Consult Packaging Section of Databook for thermal limitations and considerations of packages.

Note 1: Voltages more negative than -0.4V can be tolerated if current is limited to 50mA.

CONNECTION DIAGRAMS

DIL-20, (Top View)

LCC-28, PLCC-28 (Top View)

J or N, DW Packages

L, Q Packages

ELECTRICAL CHARACTERISTICS: Unless otherwise stated these specifications apply for TA = –40°C to +85°C for

UC2909; °0C to +70°C for UC3909; C T = 330pF, RSET = 11.5k, R10 = 10k, RTHM = 10k, VCC = 15V, Output no load, RSTAT0 = RSTAT1 = 10k, CHGENB = OVCTAP = VLOGIC, TA = TJ.

PARAMETER	TEST CONDITIONS	MIN	TYP	MAX	UNITS
Current Sense AMP (CSA) Section	VID = CS+ – CS–
DC Gain	CS– = 0, CS+ = -50mV; CS+ = –250mV	4.90	5	5.10	V/V
	CS+ = 0, CS– = 50mV; CS–- = 250mV	4.90	5	5.10	V/V
VOFFSET (VCSO – VCAO)	CS+ = CS– = 2.3V, CAO = CA–			15	mV
CMRR	VCM = –0.25 to VCC – 2, 8.8 < VCC < 14	50			dB
	VCM = –0.25 to VCC, 14 < VCC < 35	50			dB
VOL	VID = –550mV, –0.25V < VCM < VCC–2,		0.3	0.6	V
	IO = 500μA
VOH	VID = +700mV, –0.25V < VCM < VCC–2,	5.2	5.7	6.2	V
	IO = –250μA
Output Source Current	VID = +700mV, CSO = 4V		–1	–0.5	mA
Output Sink Current	VID = –550mV, CSO = 1V	3	4.5		mA
3dB Bandwidth	VID = 90mV, VCM = 0V	200			kHz

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UC2909

UC3909

ELECTRICAL CHARACTERISTICS: Unless otherwise stated these specifications apply for TA = –40°C to +85°C for

UC2909; °0C to +70°C for UC3909; C T = 330pF, RSET = 11.5k, R10 = 10k, RTHM = 10k, VCC = 15V, Output no load, RSTAT0 = RSTAT1 = 10k, CHGENB = OVCTAP = VLOGIC, TA = TJ.

PARAMETER	TEST CONDITIONS	MIN	TYP	MAX	UNITS
Current Error Amplifier (CEA) Section
IB	8.8V < VCC < 35V, VCHGENB = VLOGIC		0.1	0.8	μA
VIO (Note 2)	8.8V < VCC < 35V, CAO = CA–			10	mV
AVO	1V < VAO < 4V	60	90		dB
GBW	TJ = 25°C, F = 100kHz	1	1.5		MHz
VOL	IO = 250μA		0.4	0.6	V
VOH	IO = –5mA	4.5	5		V
Output Source Current	CAO = 4V		–25	–12	mA
Output Sink Current	CAO = 1V	2	3		mA
ICA–, ITRCK_CONTROL	VCHGENB = GND	8.5	10	11.5	μA
Voltage Amplifier (CEA) Section
IB	Total Bias Current; Regulating Level		0.1	1	μA
VIO (Note 2)	8.8V < VCC < 35V, VCM = 2.3V, VAO = VA–		1.2		mV
AVO	1V < CAO < 4V	60	90		dB
GBW	TJ = 25°C, F = 100kHz	0.25	0.5		MHz
VOL	IO = 500μA		0.4	0.6	V
VOH	IO = –500μA	4.75	5	5.25	V
Output Source Current	CAO = 4V	–2	–1		mA
Output Sink Current	CAO = 1V	2	2.5		mA
VAO Leakage: High Impedance State	VCHGENB = GND, STAT0 = 0 & STAT1 = 0,	–1		1	μA
	VAO = 2.3V
Pulse Width Modulator Section
Maximum Duty Cycle	CAO = 0.6V	90	95	100	%
Modulator Gain	CAO = 2.5V, 3.2V	63	71	80	%/V
OSC Peak			3		V
OSC Valley			1		V
Oscillator Section
Frequency	8.8V < VCC < 35V	198	220	242	kHz
Thermistor Derived Reference Section	VID = VRTHM – VR10
Initial Accuracy, VAO (RTHM = 10k)	VID = 0, R10 = RTHM =10k (Note 3)	2.2655	2.3	2.3345	V
	VID = 0, R10 = RTHM =10k, –40°C ≤TA < 0°C	2.254	2.3	2.346	V
	(Note 3)
Line Regulation	VCC = 8.8V to 35V		3	10	mV
VAO	RTHM = 138k, R10 = 10k	2.458	2.495	2.532	V
	RTHM = 138k, R10 = 10k, -40°C ≤ TA < 0°C	2.445	2.495	2.545	V
	RTHM = 33.63k, R10 = 10k	2.362	2.398	2.434	V
	RTHM = 33.63k, R10 = 10k, -40°C ≤ TA < 0°C	2.350	2.398	2.446	V
	RTHM = 1.014k, R10 = 10k	2.035	2.066	2.097	V
	RTHM = 1.014k, R10 = 10k, -40°C ≤ TA < 0°C	2.025	2.066	2.107	V
Charge Enable Comparator Section (CEC)
Threshold Voltage	As a function of VA–	0.99	1	1.01	V/V
Input Bias Current	CHGENB = 2.3V	–0.5	–0.1		μA

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