AIC1782 Dual-Battery Charge Controller FEATURES Quick and Easy Testing for Production. Sequential Charging Control of Two NiMH/NiCd Battery Packs. Reliable Sequential Fast Charge Control of Dual NiMH and/or NiCd Battery Packs, even with a Fluctuating Charging Current. Fast Charge Termination by: ∆T / ∆t , −∆V, 0 ∆V , Safety Timer, Maximum Temperature, Maximum Voltage. Safety Timer and ∆T / ∆t Detection Slope Linearly Adjustable. Battery Voltage Protection Range Selectable. Mode of Battery Temperature Protection Selectable. Protection against Battery Voltage and Battery Temperature Faults. Selectable LED Display Mode for Battery Status. Five Pulsed Trickle Charge Modes. Discharge-before-Charge Function Available to Eliminate Memory Effect. 20-pin DIP or SO Packages. DESCRIPTION Notebook and Laptop Personal Computers. Portable Power Tools and Toys. Portable Communication Equipments. Portable Video & Stereo Equipments. over battery pack B, represented by BTS and BBV pin signals. The AIC1782 automatically switches charging current to charge the standby battery pack after the battery pack being charged finishes its charging or encounters a fault condition. −∆V (-0.25%) detection, 0 ∆V (peak voltage timer) detection, and ∆T / ∆t detection are the primary methods employed by the AIC1782 to terminate fast charge. The fast charge can also be cut off by maximum battery voltage and maximum battery temperature detection along with the safety timer to prevent charging under been proved powerful in terminating fast charging reliable decision of ending fast charge and prevent 80 Cell Voltage 1.35 60 1.25 40 misaction caused by using −∆V detection alone Temperature (°C) Cell Voltage (V) sented by input signals of ATS and ABV pins, Both ∆T / ∆t and − ∆V detection methods have 100 1.45 under certain conditions. Fig. 1 shows an example of charging curve of a battery charged by a fluctuating current from a NiMH battery charger which uses the AIC1782 controller IC to achieve optimal charging. The ∆T / ∆t or −∆V detection circuitry may be disabled independently for different appli- Temperature 30 40 50 60 20 Charge Time (min.) Fig. 1 quence gives priority to battery pack A, repre- the combination of these two methods to achieve Charge Current = 600m A Cell Capaci ty = 550m A Ni MH B attery 20 After powered on, the AIC1782 charging se- for NiMH and NiCd batteries. The AIC1782 utilizes 1.55 10 and NiCd batteries without the risk of malfunction. battery itself. Dual-Battery Fast Chargers for: Mobile Phones. 0 for intelligent sequential charging of dual NiMH fault conditions of the charging system or the APPLICATIONS 1.15 The AIC1782 fast charge controller is designed Battery Charging Characteristics Resulted from an AIC1782-Controlled Charger with a Fluctuating Charging Current cations, such as system-integrated chargers, chargers with varying charge current, or battery packs lack of temperature sensing thermistor. Analog Integrations Corporation 4F, 9, Industry E. 9th Rd, Science Based Industrial Park, Hsinchu Taiwan, ROC DS-1782-00 TEL: 886-3-5772500 FAX: 886-3-5772510 www.analog.com.tw 1 AIC1782 The safety timer period, mode of battery tem- rid of memory effect of NiCd batteries without the perature protection, battery voltage protection risk of overdischarging. Test mode is provided for range, pulsed trickle charge duty, and LED dis- charger manufactures to dramatically reduce play mode are all adjustable or selectable. Dis- production test time. charge-before-charge function is included to get TYPICAL APPLICATION CIRCUIT R1 R3 R2 R27 1N4148 R28 VIN VCC FB R22 470 R4 390 R5 20/5W R21 2.7K Q1 D468 VIN + 78L05 C9 100µF R33 47K 1.5K AIC1563 1N5820 D5 R25 470 Q5 3904 R26 330 B2 D8 1N4148 + 2.2µF C12 1M R36 3 680 B C5 0.1µF VCC(5V) 5 R11 + C6 100µF C7 0.1µF R12 6 R13 VCC(5V) 7 R14 8 R24 2.7K 100K B1 A C8 0.1µF VCC(5V) R16 BBV DIS LEB2 18 R20 LED4 680 LEB1 17 R19 LED3 680 GND 16 BTS VCC SEL1 15 ADJ SEL2 SEL3 TMR MODE 9 ATS R15 19 AIC1782 R32 R10 20 SW1 2 Q7 D468 DSW ICOB VCC 5V 4 D2 1N4148 A1012 Q4 1N4148 D3 R35 ABV LED5 R37 3.9K VCC(5V) R23 330 Q3 3904 VCC(5V) IS 1N5820 D4 THERMISTOR GND 0.1/2W C11 220µF BST C10 1nF R30 220 200µH + D1 1N5821 A1012 Q2 THERMISTOR TC RS 1 C4 0.1µF 4.7µF BATTERY B SE 1N4148 L1 C3 R7 + BATTERY A 150 SC 4.7K C2 0.1µF C1 4.7µF R8 100K R6 D7 1K A1012 Q6 R29 + D6 4.7K R34 100K R17 10 LEA1 680 ICOA LEA2 14 13 12 11 R18 LED2 680 LED1 Battery Charger for Dual NiMH and NiCd Battery 2 AIC1782 ORDERING INFORMATION AIC1782 XX ORDER NUMBER PACKAGE TYPE N: PLASTIC DIP S: SMALL OUTLINE PIN CONFIGURATION AIC1782 CN ABV 1 20 DSW (PLASTIC DIP) BBV 2 19 ICOB DIS 3 18 LEB2 TEMPERATURE RANGE C= 0°C~70°C AIC1782 CS BTS 4 17 LEB1 VCC 5 16 GND ADJ 6 15 SEL1 SEL3 7 14 SEL2 TMR 8 13 MODE (PLASTIC SO) 9 12 ICOA LEA1 10 11 LEA2 ATS ABSOLUTE MAXIMUM RATINGS Supply Voltage .........................................................……………........................... 5.5V DC Voltage Applied on any Pin .......................................…………........................ 5.5V Sink Current of ICOA Pin, LEA1 and LEA2 Pins ................………...................... 20mA Sink Current of ICOB Pin, LEB1 and LEB2 Pins Operating Temperature Range ................……......................... 20mA ....................................…………................... 0°C~ 70°C Storage Temperature Range ...........................................…………......... -65°C~ 150°C TEST CIRCUIT Voltage Source - + ABV DSW BBV ICOB DIS LEB2 BTS LEB1 VCC GND Voltage Source - + YELLOW R1 560 - + Voltage Source VCC (5V) VCC V1 (0.95V) ADJ AIC1782 R3 ORANGE 560 R4 GREEN 560 R5 RED 560 VCC SEL1 VCC V2 (3V) 100K SEL3 SEL2 TMR MODE ATS ICOA LEA1 LEA2 VCC R2 - + Voltage Source RED VCC R6 560 R8 ORANGE 560 R7 GREEN 560 3 AIC1782 ELECTRICAL CHARACTERISTICS (Ta=25°°C, VCC=5V, unless otherwise speci- fied.) PARAMETER TEST CONDITIONS SYMBOL Supply Voltage VCC Supply Current ICC Battery Low Before Initial Timer After Initial Timer (SEL3>3V) Source Current Capability MAX. UNIT 4.5 5 5.5 V 1.1 0.21 0.63 0.69 0.75 (SEL3<2V) 1.1 1.2 1.3 Battery High (SEL3>3V) 2.6 2.7 2.8 (SEL3<2V) 1.9 2.0 2.1 Recommended External Resistor of TMR pin −∆V detection level w.r.t.* Peak Value V Temperature High VATS 1.35 1.45 1.55 Temperature Low VBTS 3.5 3.6 3.7 140 250 Ω 25 50 Ω MΩ ZDIS LEA1, LEA2, LEB1, LEB2, ICOA, ICOB pins ON OFF SEL3 pin DSW pin 1 ISEL3 IDSW MODE, SEL1, SEL2 pins Input Impedance mA 0.16 Output impedance of DIS Pin Output Impedance TYP. 0.11 Voltage Protection Limit Temperature Sense Limit VABV VBBV MIN. ABV, BBV, ATS, BTS, ADJ pins 5.5 16 µA µA 300 KΩ 1 RTM 2 V MΩ 100 1000 KΩ R -0.25 % *: with respected to 4 AIC1782 TYPICAL PERFORMANCE CHARACTERISTICS (Ta=25°°C, R2=100KΩ Ω, VCC=5V, refer to Test Circuit) Safety Timer vs Supply Volatge Supply Current vs Supply Voltage 1.18 Safety Timer (min.) Supply Current (mA) 81.0 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 Safety Timer vs Temperature 5.2 5.4 Supply Current vs Temperature 82.0 1.26 Supply Current (mA) Safety Timer (min.) 5.0 VCC (V) VCC (V) 81.0 80.0 1.14 1.02 0.90 79.0 0 20 40 60 80 0 20 40 60 Temperature(°C) Temperature (°C) ABV and BBV (High) Limit vs Temperature (SEL3>3V) ABV and BBV (High) Limit vs Temperature (SEL3<2V) 2.74 80 2.03 ABV, BBV (V) ABV, BBV (V) 2.02 2.70 2.66 2.62 0 20 40 Temperature (°C) 60 80 2.00 1.98 0 20 40 60 80 Temperature (°C) 5 AIC1782 TYPICAL PERFORMANCE CHARACTERISTICS (Continued) Output Impedance vs Temperature (LEA’s, LEB’s, ICO’s pins) ABV and BBV (Low) Limit vs Temperature (Before Initial Timer) 29 0.163 Output Impedance(Ω) ABV, BBV (V) 0.162 0.160 0.158 27 25 23 0 20 40 60 0 80 20 Temperature (°C) 40 60 80 Temperature(°C) ABV and BBV (Low ) limits vs Temperature (SEL3<2V, After Initial Timer) ABV and BBV (Low) limits vs Temperature (SEL3>3V, After Initial Timer) 0.710 1.22 ABV, BBV (V) ABV, BBV (V) 0.705 1.21 0.700 1.20 1.19 0.695 0 20 40 60 80 0.690 0 20 40 60 80 Temperature (°C) Temperature (°C) ATS and BTS (High) Limit vs Temperature ATS and BTS (Low) Limit vs Temperature 1.48 3.61 ATS, BTS (V) ATS, BTS (V) 3.62 3.60 1.46 1.44 3.59 3.58 0 20 40 Temperature (°C) 60 80 1.42 0 20 40 60 80 Temperature (°C) 6 AIC1782 BLOCK DIAGRAM GND VCC MODE SEL3 SEL1 SEL2 ADJ Bandgap Reference & Voltage Regulator MODE Selection Battery Voltage & Temperature Protection Setting LED Display& Trickle Charge Duty Setting TMR LEB2 LEB1 LEA2 Oscillator Timing Control Unit LEA1 Display Control Unit Charge Control State Machine Charge Control Unit ∆T/∆t Detection Setting Battery Temperature Protection ICOB ICOA DIS 13-bit A/D Discharge Control Unit Battery Voltage Protection + DSW CHARGE END ATS BTS ABV BBV PIN DESCRIPTIONS range of BTS pin is 0.29 VCC to 0.72 VCC. PIN 1: ABV - Divided battery voltage input to sense the battery voltage of pack A. PIN 2: BBV - Divided battery voltage input to sense the battery voltage of pack B. PIN 3: DIS PIN 5: VCC - Power supply input at 5V ± 10%. PIN 6: ADJ - For adjusting the slope of ∆T / ∆t . Acceptable voltage range for this pin is approximately 0.28V to 3.8V. If voltage higher than VCC - 0.3V, function of ∆T / ∆t detection is disabled. PIN 7: SEL3 - Determining the acceptable voltage range of ABV and BBV pins and mode of temperature protection function. - Push-pull output, used to control an external transistor to discharge the battery of pack B. DIS is active high when function of discharge is enabled. PIN 4: BTS - The battery cell temperature of pack B is represented as a voltage input to the AIC1782 at this pin. The acceptable voltage 7 AIC1782 PIN 8: TMR - Determining the period of safety timer with an external resistor connected to GND. PIN 9: ATS - The battery cell temperature of pack A is represented as a voltage input to the AIC1782 at this pin. the acceptable voltage range of ATS is 0.29 VCC to 0.72 VCC. PIN 10: LEA1 & PIN 11: LEA2 - Open-drained outputs used to indicate the charging status of the battery pack A. PIN 12: ICOA - Open-drained output, used to control the charging current of the battery pack A. PIN 13: MODE - Determining the mode of operation for the AIC1782. PIN 14: SEL2 & PIN 15: SEL1 PIN 16: GND - Tri-level inputs, that jointly control the LED display mode and the duty of trickle charge after the completion of fast charge. - Power ground. PIN 17: LEB1 & PIN 18: LEB2 - Open-drained outputs used to indicate the charging status of battery pack B PIN 19: ICOB - Open-drained output, used to control the charging current of the battery pack B. PIN 20: DSW - Controlling the function of discharge-before-charge of the battery pack B. (See discharge-before-charge subsection in application informations). APPLICATION INFORMATIONS THE AIC1782 OPERATION Power-on and Battery Prequalifying The AIC1782 is a sequential charger, initiating a acceptable limits of ABV and BBV are determined by the input voltage of SEL3 pin and the acceptable temperature sense voltage window for ATS and BTS are 0.29 VCC to 0.72 VCC. charge action on either battery pack A or B. When power is first applied to the AIC1782, all internal digital circuit of the AIC1782 are reset by the internal power-on-reset circuitry, the output of LED‘s (depending on the setting of SEL1 and SEL2 pins) flash 3 times to indicate the initiation of power-on. If both battery pack A and B are present when VCC is applied to the AIC1782, the charge action begins with battery pack A if conditions are acceptable. The AIC1782 controls the initiation of a charge action and checks for acceptable battery voltage and temperature prior to fast charging. If the voltage of ABV or BBV fail to fall within the predetermined acceptable limits, the corresponding battery pack enters a chargingsuspending mode. If the voltage of ATS or BTS is outside the 0.29 VCC to 0.72 VCC window, action to AIC1782 is determined by the input voltage of SEL3 pin. Condition of battery pack A is examined through the ATS and ABV pins, while battery pack B is examined through the BTS and BBV pins. The Discharge-Before-Charge 8 AIC1782 The AIC1782 provides the function of dis- In the course of fast charge, the AIC1782 con- charge-before-charge NiCd stantly monitors the battery voltage and tem- batteries which suffer from memory effect. This perature through ABV (or BBV) and ATS (or function can only be activated for pack B after BTS) pins. The fast charge process is regis- the prequalification of battery voltage and tem- tered complete when any one of the following perature, yet before the charge completion is situations is encountered, which are explained registered for fast charge cycle of pack B. below: Negative delta voltage (-∆V). Peak voltage timer ( 0 ∆V ). Delta temperature/ delta time ( ∆T / ∆t ). Maximum charge time. Maximum battery voltage. Maximum battery temperature. to precondition To trigger this function, DSW pin has to be biased to GND over 0.18 second. After discharge begins, LEB1 and LEB2 pins are both OFF, ICOB pin is ON, and DIS pin goes high to activate an external circuit to discharge the battery pack B until the voltage of BBV pin fall below 0.9V (or 0.69V, depending on the input voltage -∆ ∆V Cutoff of SEL3 pin) or DSW pin is biased to GND for The AIC1782 makes a voltage sampling at ABV over 0.18 second again. The application circuit (or BBV) pin every 4 seconds when safety timer is period is set equal to 80 minutes. If a negative included in TYPICAL APPLICATION CIRCUIT. delta voltage of 0.25% compared to its peak value is detected at ABV (or BBV) pin, the fast Fast Charge After the battery passes fault checks, charge begins on either of the batteries, the other bat- charge cycle is terminated. 0∆ ∆V Cutoff tery remains in a waiting state until the first bat- If the battery voltage stays at its peak value or tery terminates fast charge. The AIC1782 will decreases very slowly for the duration deter- automatically switch to fast charge the second mined by the peak voltage timer, which is in turn battery. The battery pack A has the priority over equal 3.7% of safety timer, the fast charge ac- battery pack B only when power is first applied tion is terminated. to the AIC1782. When fast charging begins, the initial and safety timer of the AIC1782 start counting. Functions of -∆V detection, Peak voltage timer, ∆T / ∆t detection, and maximum battery voltage are, however, disabled tempo- ∆T/∆ ∆t Cutoff The ∆T / ∆t detection of the AIC1782 is performed by sensing the decrease of ATS (or BTS) pin voltage in a specific timer interval dictated rarily until the initial timer period in the initial by the safety timer. The fast charging termi- stage of a charge cycle elapses. The initial timer nates when the decrease of ATS (or BTS) pin period is equal to 1/80 of safety timer. voltage in 56 seconds exceeds the predetermined value set by ADJ pin input. This time in- Since the low limit of acceptable ABV or BBV voltage are only about 0.16V during the initial timer period, even deeply discharged batteries can easily qualify to be fast charged subse- terval of 56 seconds is based on the assumption that voltage of ATS (or BTS) pin is sampled once for every 8 seconds, which is also determined by safety timer. quently. 14 AIC1782 Functioning of -∆V detection and peak voltage The acceptable battery voltage range of ABV timer ( 0 ∆V ) can be disabled if the MODE pin is and BBV pins and mode of temperature protec- biased to GND. Functioning of ∆T / ∆t detection can be disabled if the voltage of ADJ pin is tion function is determined by the voltage of higher than VCC - 0.3V. Maximum Safety Timer Cutoff The maximum fast charge period is determined by the safety timer, which is set by a resistor connected from TMR pin to GND. Safety timer, SEL3 pin, shown as the following: (a) SEL3 > VCC - 0.3V Acceptable ABV/BBV Range: Before initial timer: 0.16V~2.7V After initial timer: 0.69V~2.7V Temperature Protection Mode: -∆V sampling rate, and ∆T / ∆t sampling rate will be longer if the resistor value is larger. Entering charge-suspending mode when tem- When the value of the resistor is 100KΩ, the abnormal battery voltage. Latch for charge- safety timer period equals 80 minutes. This can suspending function is provided for high tem- be verified by biasing MODE pin to VCC and the perature protection, but not for low temperature measured frequency on DSW pin should be protection. perature is either too low or too high, same as around 32.8 KHz. After the safety timer period is finished, the fast charge action is terminated. (b) VCC - 1.4V> SEL3 > V cc - 0.4V 2 Acceptable ABV/BBV Range: Before initial timer: 0.16V~2.7V After initial timer: 0.69V~2.7V Maximum Voltage and Temperature Cutoff The AIC1782 guards against the maximum limits for battery voltage and temperature during Temperature Protection Mode: fast charging. If either of these limits is ex- If temperature is too high, battery charging ceeded, fast charge action is terminated. is regarded as completed. If temperature is too low, function of ∆T / ∆t detection is disabled, just as thermistor is not existing. Trickle Charge There are five different selectable duty cycles for trickle charge after the fast charge to prevent the loss of charge due to battery selfdischarging. The setting of SEL1 and SEL2 pins controls the duty cycle. This function can only be activated on the following three situation: Battery pack A is charge full and battery pack B is abnormal. Battery pack B is charge full and battery pack A is abnormal. Battery pack A and B are both charge full. (c) V cc - 0.4V>SEL3 >1.4V 2 Acceptable ABV/BBV Range: Before initial timer: 0.16V~2 V After initial timer:1.2V~2V Temperature Protection Mode: Entering charge-suspending mode when temperature is either too low or too high, same as abnormal battery voltage. Latch for charge-suspending function is provided DESIGN GUIDE ABV/BBV Range and Temperature Protection for high temperature protection, but not for low temperature protection. 15 AIC1782 (d) 0.3V> SEL3 Acceptable ABV/BBV Range: Before initial timer: 0.16V~2 V After initial timer:1.2V~2V Temperature Protection Mode: For SEL3 < (VCC/2) -0.4V, the suggested divider resistances of RA and RB for the corresponding number of battery cells are as below: If temperature is too high, battery charging BATTERY CELLS RA/RB RA(KΩ) RB (KΩ) is regarded as completed. If temperature is 2 1 240 240 too low, function of ∆T / ∆t detection is disabled, just as thermistor is not existing. 3 2 240 120 4 3 240 80 5 4 300 75 6 5 300 60 8 7 360 51 Battery Voltage Measurement The AIC1782 measures the battery voltage through ABV and BBV pins, which is connected to battery positive terminal through a resistordivider network, as shown in Fig. 2. The ac- 10 9 360 40 12 11 390 36 16 15 410 27 ceptable limit of divided battery voltage is determined by the input voltage of SEL3 pin. Battery Temperature Measurement The AIC1782 employs a negative temperature VBAT coefficient (NTC) thermistor to measure the RA ’ R6 ABV/BBV C6 AIC1782 0.1µF 100K 4.7µF RB + C5 battery s temperature. The thermistor is inherently nonlinear with respect to temperature. To reduce the effect of nonlinearity, a resistordivider network in parallel with the thermistor is recommended. A typical application circuit is Fig. 2 Battery Voltage Divider shown in Fig. 3. VCC 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 Thermistor sponding number of battery cells are as below: 5 VCC Rx vider resistances of RA and RB for the corre- ATS/BTS C7 0.1µF For SEL3 > (VCC/2) + 0.4V, the suggested di- VBAT AIC1782 Ry 16 GND Fig. 3 Battery Temperature Sense Circuit with a Negative Temperature Coefficient (NTC) Thermistor 16 AIC1782 The calculation for Rx and Ry in the circuit is as 67 5.5 29.5 following. 68 5.3 27.5 Ry / /RTH 0.29 Vcc = × Vcc Rx + (Ry / / RTH) RTH= The resistance of thermistor at upper limit of temperature protection. Ry / /RTH 0.72 Vcc = × Vcc Rx + (Ry / / RTL) RTL= The resistance of thermistor at lower limit of temperature protection. 69 5.2 25.8 70 5.0 24.3 TABLE. 2 Values of Rx and Ry at TL = -10°C TH (°C) Rx (KΩ) Ry (KΩ) 45 11.4 95.6 46 11.0 85.0 47 10.6 76.2 48 10.2 68.9 49 9.8 62.8 50 9.5 57.5 51 9.1 52.9 52 8.8 48.8 53 8.5 45.3 If temperature characteristic of the thermistor is like that of SEMITEC 103AT-2, the resistance of Rx and Ry is tabulated for different TL and TH as below. 54 8.2 42.1 55 7.9 39.4 56 7.6 36.8 57 7.4 34.6 (note: TL is lower temperature limit and TH is upper temperature limit.) 58 7.1 32.5 59 6.9 30.7 60 6.7 29.0 61 6.4 27.4 62 6.2 26.0 63 6.0 24.6 64 5.8 23.4 65 5.6 22.2 Substitution and rearranging the equations yield Rx= 2.061 × Ry = RTL × RTH RTL − RTH 5. 3 × RTL × RTH RTL − 6. 3RTH TABLE. 1 Values of Rx and Ry at TL = 0°C TH (°C) 50 51 52 53 54 55 56 Rx(KΩ) 10.1 9.7 9.4 9.0 8.7 8.4 Ry (KΩ) 551.1 300.7 204.8 153.9 122.8 101.8 8.1 86.5 57 7.8 75.0 58 7.5 66.0 59 7.2 58.7 The calculation of ADJ pin voltage is shown in 60 7.0 52.8 the following procedure followed by an example. 61 6.8 47.8 62 6.5 43.6 63 6.3 39.9 64 6.1 36.8 65 5.9 34.0 66 5.7 31.6 Setting the ADJ Pin Voltage The slope of ∆T / ∆t detection is determined by ADJ pin voltage of the AIC1782. Procedure (a) First, determine the temperature protection limits TH and TL. Then, substitute TH & TL into the following equation: 17 AIC1782 ∆V TS 0.72V CC − 0.29V CC 0.43V CC = = ∆TBASE TH − TL TH − TL TABLE. 3 ADJ Pin Voltage (TL=0°C, TH=50°C) S.T. (b) Determine the safety timer to obtain the value of ∆tBASE . 56(sec. ) ∆t BASE(sec.) = × Safety Timer (min. ) 80(min. ) (c) Determine the expected slope of ∆T / ∆t at which temperature rises y°C in x seconds and fast charge is subsequently cut off. ∆T y = ∆t x (d) Calculate the value of VADJ ∆V TS ∆T V ADJ = 25 × × × ∆t BASE ∆TBASE ∆t Example ∆T / ∆t 40 min. (2C) 80 min. (1C) 120 min. (0.67C) 0.75 1.0 1.25 (°C/min.) (°C/min.) (°C/min.) 0.37 0.5 0.63 0.75 1.0 1.25 1.12 1.5 1.87 1.5 2.0 2.5 1.87 2.5 3.12 2.25 3.0 3.75 160 min. (0.5C) 200 min. (0.4C) 240 min. (0.33C) A similar table for temperature range from 0°C to 60°C is as below. TABLE. 4 TH=60°C) S.T. ADJ Pin Voltage (TL=0°C, ∆T / ∆t 0.75 1.0 1.25 (°C/min.) (°C/min.) (°C/min.) 40 min. (2C) 0.31 0.42 0.52 80 min. (1C) 0.62 0.84 1.05 120 min. (0.67C) 0.94 1.25 1.56 ∆TBASE 50 − 0 which means that VTS decreases 43mV as temperature rises 1°C. 160 min. (0.5C) 1.25 1.67 2.08 200 min. (0.4C) 1.56 2.08 2.60 (b) If safety timer is equal to 80 minutes, ∆tBASE 240 min. (0.33C) 1.87 2.5 3.12 (a) Let TH=50°C, TL=0°C, VCC =5V. We have ∆V TS = 0. 43 × 5 = 0. 043 V / ° C is then 56 seconds. (c) If fast charge should be terminated when temperature rises 1°C in 60 seconds, then Setting the Period of Safety Timer The AIC1782 provides a method for linearly 1 = 0. 0166 60 adjusting the period of safety timer with an ex- (d) VADJ =25 x 0.043 x 0.0166 x 56 = 1(V) The relation between safety timer length and ∆T / ∆ t = If the temperature range is from 0°C to 50°C, the voltage of VADJ under different setting conditions should be set as tabulated below. ternal resistor connected from TMR pin to GND. the external resistor (RTMR) is shown in Fig. 4. The table following shows the resistor values for some of the commonly chosen safety timer periods. Also shown in the table is their corresponding oscillator frequencies. 18 AIC1782 ABLE. 5 The Operating Mode of AIC1782 800 RTMR (KΩ) 600 MODE pin Mode Function VCC Test Safety timer period scaled down to 1/32.... etc. Floating Normal Normal operation GND AC 400 200 0 –∆V detection disabled The Mode of LED Display and Trickle Charge 0 100 200 300 400 500 Safety Timer (min.) Fig. 4 Safety Timer vs RTMR The AIC1782 provides two LED display modes and five pulsed trickle charge modes. The modes of LED display and trickle charge are RTMR (KΩ) 11 23 48 74 100 152 206 314 491 667 Osc.Freq. (KHz) 262.4 131.2 65.6 43.7 32.8 21.9 16.4 10.9 7.3 5.5 Safety timer (min.) 10 20 40 60 80 120 160 240 360 480 Selecting Mode of Operation The AIC1782 provides three modes of opera- tion: normal, test, and AC mode, determined by the setting of MODE pin according to TABLE 5. The AIC1782 will operate normally when the MODE pin is left floating (a 0.1µF capacitor is recommended to be tied to MODE pin if the determined by the tri-level inputs, SEL1 and SEL2 pins, as in the TABLE 6. TABLE. Charge SEL1 VCC Floating GND 6 Mode of LED Display and Trickle SEL2 Trickle Charge LED Duty Display Mode VCC N/A Type 1 Floating 1/32 Type 1 GND 1/64 Type 1 VCC 1/128 Type 1 Floating 1/256 Type 1 GND N/A Type 2 VCC 1/32 Type 2 Floating 1/64 Type 2 GND 1/128 Type 2 Displaying the Battery Charging Status charge circuit works in a noisy environment). The AIC1782 provides four open-drained outputs, When the MODE pin is biased to GND, the in which LEA1 and LEA2 are used to indicate the function of − ∆V detection is disabled. When the MODE pin is biased to VCC, the AIC1782 enters the test mode. The test mode can be used to significantly reduce production test time. For relevant informations please contact AIC directly. battery charging status of pack A, yet LEB1 and LEB2 are used to indicate battery charging status of pack B. Refer to the table of LED display mode (TABLE 6), depending on the setting of SEL1 and SEL2 pins, the outputs of LEA1, LEA2, LEB1, and LEB2 pins are shown in the following table: 19 AIC1782 TYPE 1 LEA1/ Power On Wait Charge Full Abnormal 1HZ ON ON OFF OFF LEB1 LEA2/ Power Wait Fast Charge Fault ON ON Charging Completed Conditions ICOA/ ON ICOB OFF ON OFF ON ON OFF See pin 14 & 15 ON OFF LEB2 Test Mode TYPE 2 LEA1/ Power On Wait Charge Full Abnormal 1HZ 1HZ ON OFF 4HZ controlled ADJ, ABV, BBV, ATS, BTS, SEL1 and SEL2 pin voltages of a recommended AIC1782 test scheme, utilizing TEST mode function. Out- LEB1 LEA2/ Fig. 5 shows the timing diagram for externally 1HZ 1HZ 4HZ ON OFF LEB2 put waveforms of LEA1, LEA2, LEB1, LEB2, ICOA and ICOB of a properly functioning AIC1782 are also shown in the figure. For detailed information please consult with AIC staffs Charging Current Control directly. As shown in the typical application circuit, the AIC1782 offers two open-drained output pins, ICOA and ICOB pins, to control the charging current of battery pack A and pack B. When fast charge is completed, the AIC1782 enters the trickle charge mode. In trickle charge mode, the ICOA or ICOB pins output switch with predetermined duty cycle. Refer to the table of trickle charge mode (TABLE 6), the duty cycle is determined by the setting of SEL1 and SEL2 pins. The following table summarizes how ICOA and ICOB pins correspond to various charging states. 20 AIC1782 TIMING DIAGRAM VCC, SEL3, MODE=5V, (DSW FREQ.=820KHz, 25 TIMES of 32.8K) Power Init. PEAK TIMER TEST ON -∆V TEST 5V ADJ SAFETY TIMER TEST ∆T/∆t TEST -∆V DISALBE TEST 1.12V 3V <2.1V (-0.15%) 1.95V 2V (A):ABV (B):BBV 2V 1.997V 1.9V 1.5V (A):ATS (B):BTS 2V 2V (-0.15%) 1.997V 1.997V 1.993V (-0.35%) 4V 4V 4V 2V 2V 1.96V 0V ON ON OFF ON OFF OFF ON SEL1 SEL2 Floating Floating VCC Floating 0.1 0.14 0.12 1 0.74 2 0 0.14 0.26 6.01 ON 3.2KHz ON (A):ICOA (B):ICOB OFF OFF ON OFF (A):LEA2 (B):LEB2 2V 2mV Step/100mS (-2.5%) OFF ON (A):LEA1 (B):LEB1 TIME (B) (SEC.) STAGE 1.85V (-2.15%) OFF 4V <2.1V 2V TIME (A) (SEC.) STAGE 2mV Step/100mS 0.1 0.14 0.12 11 12 6.11 6.25 6.37 0.26 0.12 3 4 1 0.74 1.26 1.38 0.32 1.17 Floating GND 0.32 0.12 5 6 0.32 0.97 0.5 0.24 7 2.02 2.14 0.26 Delay 0.3 13 14 7.21 7.47 GND Floating 2.46 3.43 0.4 1.32 8 9 3.93 4.17 0.5 0.24 15 7.77 GND GND 4.57 Floating Floating 0.1 0.02 10 5.89 5.99 6.01 0.4 16 8.27 8.51 8.91 Fig. 5 Timing Diagram of AIC1782 in Test Mode 21 AIC1782 PHYSICAL DIMENSIONS 20 LEAD PLASTIC DIP (unit: mm) D SYMBOL MIN MAX A1 0.381 — A2 2.92 4.96 b 0.35 0.56 C 0.20 0.36 D 24.89 26.93 E 7.62 8.26 E1 6.09 7.12 E1 E A1 A C L e eB e b 2.54(TYP) eB — 10.92 L 2.92 3.81 20 LEAD PLASTIC SO (300 mil) (unit: mm) D H E e B SYMBOL MIN MAX A 2.35 2.65 A1 0.10 0.30 B 0.33 0.51 C 0.23 0.32 D 12.60 13.00 E 7.40 7.60 e A A1 C L 1.27(TYP) H 10.00 10.65 L 0.40 1.27 22