AIC1783 Battery Charge Controller n FEATURES n DESCRIPTION l Fast Charge Control of NiMH/NiCd Batteries. The AIC1783 fast charge controller IC is designed l Fast Charge Termination by: − ? V , 0 ? V , Safety for intelligent charging of NiMH or NiCd batteries Timer, Maximum Voltage. without the risk of overcharge. − ? V detection l Protection against Battery Voltage Fault. (-0.25%) and 0 ? V detection (peak voltage timer) l Pulsed Trickle Charge Mode. are the primary methods employed l Quick and Easy Testing for Production. AIC1783 to terminate fast charge. The fast charge l 8-pin DIP or SO Packages. can also be cut off by maximum battery voltage by the along with the safety timer to prevent charging n APPLICATIONS under fault conditions of the charging system or the battery itself. Battery Fast Chargers for: l Mobile Phones. l Notebook and Laptop Personal Computers. l Portable Power Tools and Toys. l Portable Communication Equipment. l Portable Video & Stereo Equipment. The safety timer period is adjustable for flexible usage that AIC1783 could be applied in the wide range of battery capacity. Test mode is provided for charger manufactures to dramatically reduce production test time. n TYPICAL APPLICATION CIRCUIT U1 7805 1 VIN C5 1µF 1N4148 D3 VIN + VOUT GND 3 + C6 2 10µF LED1 R4 120K 1 L1 R13 D1 1N5822 U3 R9 1 390K 2 C7 DC DE IS 3 CF VCC 4 GND 1000P C2 220µF D4 BOOST FB 8 7 6 R2 D2 IN4148 C3 0.1µF BAT1 BATTERY + 120/0.5W RED 1N5822 220µH 1µF 100K R1 1K C1 R3 240K R11 100K R5 C4 120K 0.1µF + C9 4.7µF C10 R12 47nF 150K U2 REF VCC 2 TIMER VBT 3 MODE ICON 4 GND LED 8 R6 R7 7 680 47K 6 R8 10K Q1 5 2N222 AIC1783 R10 0.3/5W 5 AIC1563 + C8 220µF Battery Charge Circuit with Wide Input Voltage Range Analog Integrations Corporation 4F, 9, Industry E. 9th Rd, Science Based Industrial Park, Hsinchu Taiwan, ROC DS-1783-00 TEL: 886-3-5772500 May 28, 01 FAX: 886-3-5772510 www.analog.com.tw 1 AIC1783 n ORDERING INFORMATION AIC1783C X ORDER NUMBER PIN CONFIGURATION AIC1783CN (PLASTIC DIP) PACKAGE TYPE N: PLASTIC DIP S: SMALL OUTLINE AIC1783CS (PLASTIC SO) REF 1 8 VCC TIMER 2 7 VBT MODE 3 6 ICON GND 4 5 LED n ABSOLUTE MAXIMUM RATINGS Supply Voltage ............................................… … … … ........................................ 5.5V DC Voltage Applied on any pin ......................… … … … … ...................................... 5.5V Sink current of ICON pin, LED1 and LED2 pin .......................… … … .................. 20mA Operating Temperature Range .............................................… … … ...... Storage Temperature Range .............................................… … … … ...... -40C~ 85°C -65°C~ 150°C n TEST CIRCUIT 5V 1 100K 2 3 RTIMER 100K 120K REF VCC TIMER VBT 8 5V + 7 680 MODE ICON 4 GND LED - VOLTAGE SOURCE 6 5 680 AIC1783 RED GREEN 5V 2 AIC1783 n ELECTRICAL CHARACTERISTICS (Ta=25°C, V PARAMETER =5V, unless otherwise specified.) SYMBOL MIN. TYP. MAX. UNIT Supply Voltage VCC 4.5 5.0 5.5 V Supply Current ICC Voltage Protection Limit TEST CONDITIONS CC Battery Low During Initial Timer After Initial Timer VBT Battery High Output Impedance Input Impedance LED, ICON Pins ON OFF 0.16 0.69 0.21 0.75 2.6 2.7 2.80 25 50 1 300 pin Recommended External Resistor of TIMER pin V Ω MΩ KΩ 1 RTIMER VBT=2V mA 0.11 0.63 MODE pin VBT -∆V Detection accuracy 1.1 MΩ 2 100 1000 KΩ -0.15 -0.25 -0.35 % 3 AIC1783 n TYPICAL PERFORMANCE CHARACTERISTICS (Ta=25°C, RTIMER =100KΩ , VCC =5V, refer to Test Circuit) Safety Timer vs Supply Volatge Supply Current vs Supply Voltage 1.21 81.0 Safety Timer (min.) Supply Current (mA) 1.18 1.12 1.06 80.5 80.0 79.5 1.00 4.4 4.6 4.8 5.0 5.2 79.0 5.4 4.4 4.6 4.8 5.0 5.2 VCC (V) VCC (V) LED Flashing Frequency vs Supply Voltage Supply Current vs Temperature 5.4 4.8 1.26 Supply Current (mA) Frequency (Hz) 4.6 4.4 4.2 1.14 1.02 4.0 3.8 0.9 4.4 4.6 4.8 5.0 5.2 0 5.4 20 VCC (V) 40 Temperature (°C) 60 80 LED Flashing Frequency vs Temperature Safety Timer vs Temperature 5.0 82.0 Frequency (Hz) Safety Timer (min.) 4.6 81.0 4.2 80.0 3.8 79.0 0 20 40 Temperature(°C) 60 80 3.4 0 20 40 60 80 Temperature( °C) 4 AIC1783 n TYPICAL PERFORMANCE CHARACTERISTICS (Continued) V BT(LOW) Limits vs Temperature ( After Initial Timer) V BT (high) Limit vs Temperature 2.74 0.700 0.695 VBT (V) VBT (V) 2.70 0.690 2.66 0.685 2.62 0 20 40 Temperature ( °C) 60 0 80 20 60 80 Output Impedance vs Temperature (LED,ICON pins) VB T (low) Limit vs Temperature (During Initial Timer) 29 Output Impedance(Ω) 0.163 0.162 VB T (V) 40 Temperature (°C) 0.161 0.160 0.159 0.158 27 25 23 0 20 40 Temperature (°C) 60 80 0 20 40 Temperature (°C) 60 80 5 AIC1783 n BLOCK DIAGRAM MODE MODE Selection GND VCC Bandgap Reference & Voltage Regulator REF LED Oscillator Display Control Unit Charge Control Battery Voltage Protection Setting TIMER ICON State Machine 13-bit A/D Charge Control Unit Battery Voltage Protection VBT n PIN DESCRIPTIONS PIN 1: REF- Reference voltage input, PIN 5: LED- acceptable voltage range : indicate the battery charging (V CC -1.4V) ~ (0.5V CC -0.4V) status. PIN 2: TIMER- Determining the period of PIN 6: ICON- Open-drained output, used to safety timer with an external control the charging current to resistor connected to GND. the battery. PIN 3: MODE- Determining the mode of PIN 7: VBT- operation for the AIC1783. PIN 4: GND- Open-drained output used to Power ground. Divided battery voltage input to sense the battery voltage. PIN 8: VCC- Power supply input at 5V±10%. 6 AIC1783 n APPLICATION INFORMATIONS OPERATION l Maximum charge time l Maximum battery voltage Power-On and Battery Pre-qualifying When power is first applied to the AIC1783, all -∆V Cutoff internal digital circuit blocks of the AIC1783 are The AIC1783 makes a voltage sampling at VBT pin reset by the internal power-on-reset circuitry and every 4 seconds when safety timer period is set output LED flash 3 times to indicate the initiation of equal to 80 minutes. If a negative delta voltage of power-on. The internal control unit then examines 0.25% compared to its peak value is detected at the battery condition through the VBT pin. VBT pin, the fast charge cycle is terminated. The acceptable range of VBT pin is 0.16V to 2.7V. If 0∆V Cutoff the voltage of VBT pin fails to fall within the predetermined acceptable limits, the AIC1783 enters a charge-suspending mode, in which all the internal circuitry remains in reset state. by the peak voltage timer which is 6% of safety timer, Maximum Safety Timer Cutoff After the battery passes fault checks, fast charging begins while initial timer and safety timer of the start decreases very slowly for the duration determined the fast charge action is terminated. Fast Charge AIC1783 If the battery voltage stays at its peak value or counting. Functions of −? V detection, peak voltage timer, and maximum battery voltage are, however, disabled temporarily until the initial timer period in the initial stage of a charge cycle elapses. The initial timer period is equal to 1/80 of safety timer. Since the low limit of acceptable VBT voltage is only about 0.16V during the initial timer period, even deeply discharged batteries can easily qualify to be fast charged subsequently. The maximum fast charge period is determined by the safety timer, which is set by a resistor connected from TIMER pin to GND. Safety timer, −? V sampling rate will be longer if the resistor value is larger. When the value of the resistor is 100KΩ, the safety timer period equals 80 minutes. After the safety timer period is finished, the fast charge action is terminated. Maximum Voltage Cutoff The AIC1783 guards against the maximum limits for battery voltage during fast charging. If either of these limits is exceeded, fast charge action is terminated. In the course of fast charge, the AIC1783 constantly monitors the voltages at VBT pin. The fast charge process is switched to trickle charge when any one of the following situations is encountered, which are explained below: l Negative delta voltage ( − ? V ) l Peak voltage timer ( 0 ? V ) Trickle Charge The trickle charge after the fast charge to prevent the loss of charge due to battery self-discharging. The duty cycle is set to 1/128 by internal circuitry. 7 AIC1783 The functions and charging states control mentioned above are illustrated in the function flow chart of AIC1783 (Fig. 2) Setting the Period of Safety Timer The AIC1783 provides a method for linearly adjusting the period of safety timer with an external resistor connected from TIMER pin to GND. The relation between safety timer length and the external resistor (RTIMER ) is shown in Fig. 3. The DESIGN GUIDE table following shows the resistor values for some of the commonly chosen safety timer periods. Also Battery Voltage Measurement shown in the table are their corresponding oscillator The AIC1783 measures the battery voltage through frequencies. VBT pin, which is connected to battery positive terminal through a resistor-divider net work, as 800 shown in Fig. 1 600 RTIMER (KΩ) VBAT RA R5 200 VBT C6 0.1µF 100K + C5 4.7µF RB 7 400 AIC1783 0 0 200 300 400 500 Safety Timer (min.) Fig. 3 FIG. 1 100 Safety Timer vs. RTIMER Battery Voltage Divider The suggested divider resistance of RA and RB for the corresponding number of battery cells are as below: BATTERY CELLS RA/RB RA (KΩ) RB (KΩ) 2~4 2 240 120 3~6 3.3 300 91 4~8 4.9 300 62 5~10 6.4 300 47 6~12 7.8 310 39 8~16 10.8 390 36 8 AIC1783 Power ON LED Flash 3 Times If VBT in Normal Range No LED Displays Abnormal, ICON ON, Safety Timer Reset Yes Charging (ICON OFF) No If Initial Timer Finished Yes If VBT in Normal Range No Yes If 0Δ V is Detected LED Display Fast Charge ICON OFF Yes Yes No If -0.25% ΔV is Detected Yes LED Display Battery Fulll, Fast Charge Finished, Trickle Charge Starts Battery Replacement No No No If Safety Timer Period has Finished Fig. 2 Yes Function Flow Chart of AIC1783 9 AIC1783 RTIMER (KΩ) Display the Battery Charging Status OSC. Safety timer Freq.(KHz) (min.) The AIC1783 provides an open-drained output, LED 11 262.4 10 pin, to indicate the battery charging status. The 23 131.2 20 outputs of LED pin are shown in the following table: 48 65.6 40 74 43.7 60 Power 100 32.8 80 ON 152 21.9 120 206 16.4 160 314 10.9 240 491 7.3 360 667 5.5 480 LED 1Hz Fast Charge Fault Charging Completed Conditions 4Hz ON Flashing OFF Charging Current Control As shown in the typical application circuit, the AIC1783 offers an open-drained output pin, ICON Selecting Mode of Operation pin, to control the charging current flow in fast The AIC1783 provides three modes of operation: charge state and switch on to inhibit the charging normal, test, and AC mode determined by the current flow in fault conditions. When fast charge is setting of MODE pin. The AIC1783 will operate completed, the AIC1783 enters the trickle charge normally when the MODE pin is left floating (a 0.1µF mode. In trickle charge mode, the ICON pin output capacitor is recommended to be tied to MODE pin if switches with 1/128 duty cycle. the charge circuit works in a noisy environment). When the MODE pin is biased to GND, the function Power Fast Charge Fault of -∆V detection is disabled. When the MODE pin is ON Charging Completed Conditions ON OFF biased to VCC , the AIC1783 enters the test mode. The test mode can be used to significantly reduce ICON 1/128 ON Duty cycle production test time. MODE pin Mode VCC Test Function Safety timer period scaled down to 1/32 Floating GND Normal Normal operation AC –∆V detection disabled 10 AIC1783 n PHYSICAL DIMENSIONS l 8 LEAD PLASTIC SO (unit: mm) D SYMBOL MIN MAX A 1.35 1.75 A1 0.10 0.25 B 0.33 0.51 C 0.19 0.25 D 4.80 5.00 E 3.80 4.00 H E e e 1.27(TYP) A A1 C B l H 5.80 6.20 L 0.40 1.27 L 8 LEAD PLASTIC DIP (unit: mm) D E1 E A2 A1 C L eB b SYMBOL MIN MAX A1 0.381 — A2 2.92 4.96 b 0.35 0.56 C 0.20 0.36 D 9.01 10.16 E 7.62 8.26 E1 6.09 7.12 e 2.54 (TYP) eB — 10.92 L 2.92 3.81 e 11