SS6783ACSTR

SS6783A(G) Battery Charge Controller for Low Power Charging FEATURES Fast charge control of NiMH/NiCd batteries. Fast charge termination by: − ∆V, 0 ∆V safety timer, or maximum voltage. Protection against battery voltage faults. Pulsed trickle-charge mode. Quick and easy testing for production. 8-pin DIP or SO packages. DESCRIPTION The SS6783A fast charge controller IC is designed for intelligent charging of NiMH or NiCd batteries without the risk of overcharge. -D V detection (-0.25%) and 0D V detection (peak) voltage timer) are the primary methods employed by the SS6783A to terminate fast charging. Fast charging c an also be cut off u sing the maximum battery voltage along with the safety timer to prevent charging under fault conditions of the charging system or the battery itself. The safety timer period is adjustable for flexible usage allowing the SS6783A to be used with a wide range of battery capacities. A test mode is provided for charger manufacturers to dramatically reduce production test time. APPLICATIONS Battery Fast Chargers for: Mobile Phones. Notebook and Laptop Personal Computers. Portable Power Tools and Toys. Portable Communication Equipment. Portable Video & Stereo Equipment. This device is available with Pb-free lead finish (second-level interconnect) as SS6783AGS. TYPICAL APPLICATION CIRCUIT VIN=5V R3 10K D3 LL4148 R7 100K U1 1 REF 2 TIMER C3 0.1µF R8 120K 2SC4672 R2 0.5 Q1 R1 680 + D1 D2 R4 68K R5 220K LED1 VCC 8 VBT 7 R10 680 R6 100K C2 4.7µF LL4148 LL4148 C1 47µF 2-Cell NiMH/NiCd R9 3 MODE ICON 6 200K 4 GND LED 5 SS6783A *Note: ICHARGE=380mA @VBAT=2.8V Linear Charger for 2-Cell NiMH/NiCd Batteries 1/11/2005 Rev.2.10 www.SiliconStandard.com 1 of 12 SS6783A(G) ORDERING INFORMATION SS6 783AXXXX PIN CONFIGURATION T OP VIEW REF 1 TIMER P acking TR: T ape and reel (not for PDIP-8 (CN)) TB: T ubes P ackage type N: P lastic PDIP-8 (only available in tubes) S: S mall outline SO-8 C : C ommercial G : C ommercial, Pb-free lead finish (Available for SO-8 (GS) o nly) Example s : S S67 83 A CSTR in SO-8 p ackage , shipped on tape and reel S S6 783 AG STR in SO-8 p ackage w ith Pb-free lead finish, shipped on tape and reel 8 7 6 5 VCC VBT ICON LED 2 MODE 3 GND 4 ABSOLUTE MAXIMUM RATINGS Supply Voltage ....................................…….......…………........................................ 5.5V DC Voltage Applied on any pin ......................……………...................................... 5.5V Sink current of ICON pin, LED pin ............……………….........……….................. 20mA Operating Temperature Range .............................................………...... -40°C~ 85°C Storage Temperature Range .............................................…………...... -65°C~ 150°C TEST CIRCUIT 5V 1 REF TIMER MODE GND SS6783A VCC VBT ICON LED 8 7 6 5 5V 100k 2 3 4 + 680 680 - VOLTAGE SOURCE RTIMER 100k 120k RED GREEN 5V 1/11/2005 Rev.2.10 www.SiliconStandard.com 2 of 12 SS6783A(G) ELECTRICAL CHARACTERISTICS PARAMETER Supply Voltage Supply Current Battery Low During Initial Timer After Initial Timer Battery High LED, ICON Pins Output Impedance ON OFF MODE pin VBT pin RTIMER 1 2 100 1000 25 1 300 50 Ω MΩ kΩ MΩ kΩ (TA=25°C, VCC=5V, unless otherwise specified.) SYMBOL VCC ICC MIN. 4.5 TYP. 5.0 1.1 MAX. 5.5 UNIT V mA TEST CONDITIONS Voltage Protection Limit VBT 0.11 0.63 2.6 0.16 0.69 2.7 0.21 0.75 2.80 V Input Impedance Recommended External Resistor of TIMER pin − ∆V Detection accuracy VBT=2V -0.15 -0.25 -0.35 % 1/11/2005 Rev.2.10 www.SiliconStandard.com 3 of 12 SS6783A(G) TYPICAL PERFORMANCE CHARACTERISTICS VCC=5V, refer to Test Circuit) 1.08 81.5 81.0 1.02 (TA=25°C, RTIMER=100kΩ, Supply Current (mA) Safety Timer (min) 4.6 4.8 5.0 5.2 5.4 80.5 80.0 79.5 79.0 78.5 0.96 0.90 0.84 4.4 78.0 4.4 4.6 4.8 5.0 5.2 5 .4 5.6 VCC (V) Fig. 1 Supply Current vs. Supply Voltage VCC (V) Fig. 2 Safety Timer vs. Supply Voltage 4.4 1.05 Supply Current (mA) Frequency (Hz) 4.2 1.00 0.95 4.0 0.90 3.8 0.85 3.6 4.4 4.6 4.8 5.0 5.2 5 .4 5.6 0.80 0 20 40 60 80 VCC (V) Fig. 3 LED Flashing Frequency vs. Supply Voltage Temperature (°C) Fig. 4 Supply Current vs. Temperature 82 81 5.0 4.8 Safety Timer (min) 80 79 78 77 76 75 Frequency (Hz) 4.6 4.4 4.2 4.0 3.8 3.6 3.4 -20 0 20 40 60 80 0 Temperature (°C) Fig. 5 Safety Timer vs. Temperature Temperature (°C) 20 40 60 80 Fig. 6 LED Flashing Frequency vs. Temperature 1/11/2005 Rev.2.10 www.SiliconStandard.com 4 of 12 SS6783A(G) TYPICAL PERFORMANCE CHARACTERISTICS 2.80 0.84 (Continued) 2.76 0.80 VBT (V) 2.72 VBT (V) 0 20 40 60 80 0.76 2.68 0.72 2.64 0.68 2.60 0.64 0 20 40 60 80 Temperature (°C) Fig. 7 VBT (High) Limit vs. Temperature Temperature (°C) Fig. 8 VBT (Low) Limit vs. Temperature (After Initial Timer) 33 0.20 Output Impedance (W ) 0 20 40 60 80 0.18 30 VBT (V) 0.16 27 0.14 24 0.12 21 0 20 40 60 80 Fig. 9 Temperature (°C) VBT (Low) Limit vs. Temperature (During Initial Timer) Temperature (°C) Fig.10 Output Impedance vs. Temperature (LED, ICON Pins) 1/11/2005 Rev.2.10 www.SiliconStandard.com 5 of 12 SS6783A(G) BLOCK DIAGRAM MODE GND VCC TIMER MODE Selection Bandgap Reference & Voltage Regulator LED Oscillator Display Control Unit Charge Control REF Battery Voltage Protection Setting State Machine ICON Charge Control Unit 13-bit A/D Battery Voltage Protection VBT PIN DESCRIPTIONS PIN 1: REFReference voltage input, PIN 5: LEDOpen-drain output used to indicate the battery charging status. of PIN 6: ICON- Open-drain output, used to control the charging current to the battery. of PIN 7: VBTPIN 8: VCCDivided battery voltage input to sense the battery voltage. Power supply input at 5V±10%. acceptable voltage range : (VCC-1.4V) ~ (0.5VCC+0.4V) PIN 2: TIMER- Determining the period safety timer with an external resistor connected to GND. PIN 3: MODE- Determining PIN 4: GNDPower ground. the mode operation for the SS6783A. 1/11/2005 Rev.2.10 www.SiliconStandard.com 6 of 12 SS6783A(G) APPLICATION INFORMATION OPERATION Power-On and Battery Pre-Qualifying When power is first applied to the SS6783A, all internal digital circuit blocks of the SS6783A are reset by the internal power-on-reset circuitry and the output LED flashes 3 times to indicate the initiation of power-on. The internal control unit then examines the battery condition through the VBT pin. The acceptable range of VBT pin is 0.16V to 2.7V. If the voltage of VBT pin fails to fall within the predetermined acceptable limits, the SS6783A enters a charge-suspending mode, in which all the internal circuitry remains in reset state. Fast Charge After the battery passes fault checks, fast charging begins while the initial timer and safety timer of the SS6783A start counting. The 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 the 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 subsequently fast charged. In the course of fast charge, the SS6783A 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: Negative delta voltage ( − ∆V ) Peak voltage timer ( 0 ∆V ) Maximum charge time Maximum battery voltage -∆V Cutoff The SS6783A makes a voltage sampling at VBT pin every 4 seconds when safety timer period is set equal to 80 minutes. If a negative delta voltage of 0.25% compared to its peak value is detected at VBT pin, the fast charge cycle is terminated. 0∆V Cutoff If the battery voltage stays at its peak value or decreases very slowly for the duration determined by the peak voltage timer which is 6% of safety timer, the fast charge action is terminated. Maximum Safety Timer Cutoff 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 SS6783A guards against the maximum limits for battery voltage during fast charging. If either of these limits is exceeded, fast charge action is terminated. Trickle Charge Trickle charge starts after the fast charge to prevent the loss of charge due to battery self-discharge. The duty cycle is set to 1/128 by internal circuitry. 1/11/2005 Rev.2.10 www.SiliconStandard.com 7 of 12 SS6783A(G) The functions and charging state control mentioned above are illustrated in the function flow-chart of the SS6783A (Fig. 12) Setting the Period of Safety Timer The SS6783A provides a method for linearly adjusting the period of the 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. 13. The table following shows the resistor values for some of the commonly chosen safety timer periods. Also shown in the table are their corresponding oscillator frequencies. DESIGN GUIDE Battery Voltage Measurement The SS6783A measures the battery voltage through VBT pin, which is connected to the battery positive terminal through a resistor-divider network, as shown in Fig. 11. VBAT RA R5 + C5 100k 4.7µF C6 0.1µF 7 VBT SS6783A 800 600 RTIMER (kΩ) 400 200 RB 0 0 100 200 300 400 500 Safety Timer (min.) Fig. 11 Battery Voltage Divider The suggested divider resistance of RA and RB for the corresponding number of battery cells are as below: TABLE 1 BATTERY CELLS 2~4 3~6 4~8 5~10 6~12 8~16 RA/RB 2 3.3 4.9 6.4 7.8 10.8 RA (kΩ) 240 300 300 300 310 390 RB (kΩ) 120 91 62 47 39 36 Fig. 13 Safety Timer vs. RTIMER 1/11/2005 Rev.2.10 www.SiliconStandard.com 8 of 12 SS6783A(G) Power ON LED Flash 3 Times If VBT in Normal Range Yes If Initial Timer Finished No LED Displays Abnormal, ICON ON, Safety Timer Reset Charging (ICON OFF) No Yes If VBT in Normal Range No Yes If 0∆V is Detected Yes LED Display Fast Charge (ICON OFF) No LED Display Battery Fulll, Fast Charge Finished, Trickle Charge Starts Yes If -0.25% ∆V is Detected Yes Battery Replacement No No No If Safety Timer Period has Finished Yes Fig. 12 Function Flow Chart of SS6783A 1/11/2005 Rev.2.10 www.SiliconStandard.com 9 of 12 SS6783A(G) TABLE 2 RTMR (kΩ) 11 23 48 74 100 152 206 314 491 667 OSC. Freq.(kHz) 256 131 65.8 43.1 32.8 21.6 16.0 10.6 6.89 5.04 Safety timer (min.) 10 20 40 60 80 120 160 250 380 520 Charging Current Control As shown in the typical application circuit, the SS6783A offers an open-drain output at the ICON pin, to control the charging current flow in fast charge state and switch on to inhibit the charging current flow in fault conditions. When fast charge is completed, the SS6783A enters the trickle charge mode. In trickle charge mode, the ICON pin output switches with 1/128 duty cycle. Power ON ICON ON Fast Charging OFF Charge Completed 1/128 Duty cycle Fault Conditions ON LED Display the Battery Charging Status The SS6783A provides an open-drain output at the LED pin, to indicate the battery charging status. The outputs of LED pin are shown in the following table: Power ON 1Hz Fast Charge Fault Charging Completed Conditions 4Hz Flashing ON OFF Selecting Mode of Operation The SS6783A provides three modes of operation: normal, test, and AC mode determined by the setting of MODE pin. The SS6783A will operate normally when the MODE pin is left floating (a 0.1µF capacitor is recommended to be tied to MODE pin if the charge circuit works in a noisy environment). When the MODE pin is biased to GND, the function of -∆V detection is disabled. When the MODE pin is biased to VCC, the SS6783A enters the test mode. The test mode can be used to significantly reduce production test time. TABLE 3 MODE pin VCC Floating GND Mode Test Normal AC Function Safety timer period scaled down to 1/32 Normal operation -∆V detection disabled 1/11/2005 Rev.2.10 www.SiliconStandard.com 10 of 12 SS6783A(G) APPLICATION EXAMPLE U1 VIN 11~15V 1N4148 D3 78L05 VIN VOUT GND C5 1µF R1 1K 220µH SS24 R2 BAT1 **BATTERY 240K R11 100K R5 120K C4 0.1µF + + + C6 10µF R3 100K R4 120K U2 1 REF 2 TIMER 3 MODE VCC VB T ICON LED 8 7 6 5 Q1 MMBT2222A LED1 RED L1 C1 1µF R10 120/0.25W U3 DC DE CF GND SS6563 BOOST IS D4 + R6 680 R7 47K D1 SS24 C2 D2 C3 0.1µF R8 10K 220µF R9 390K 1 2 3 8 7 IN4148 RS 0.5/0.25W + C9 4.7µF C10 47nF R12 150K 4 GND SS6783A VCC 6 FB C7 470P 4 5 C8 220µF **: 2~4 NiMH/NiCd cells Note: Charge Current: 0.3V/Rs Ampere Safety Timer: 120 min Fig. 14 Switching Battery Charger Circuit with Wide Input Voltage Range 1/11/2005 Rev.2.10 www.SiliconStandard.com 11 of 12 SS6783A(G) PHYSICAL DIMENSIONS (unit: mm) 8 LEAD PLASTIC SO (CS/GS D SYMBOL A H E MIN 1.35 0.10 0.33 0.19 4.80 3.80 5.80 0.40 MAX 1.75 0.25 0.51 0.25 5.00 4.00 6.20 1.27 A1 B C D E e A C e H L L 1.27(TYP) B 8 LEAD PLASTIC DIP D (CN) SYMBOL A1 E1 A1 MIN 0.381 2.92 0.35 0.20 9.01 7.62 6.09 — 2.92 MAX — 4.96 0.56 0.36 10.16 8.26 7.12 10.92 3.81 A2 b C E D E C A2 A1 L E1 e eB L 2.54 (TYP) eB b e Information furnished by Silicon Standard Corporation is believed to be accurate and reliable. However, Silicon Standard Corporation makes no guarantee or warranty, express or implied, as to the reliability, accuracy, timeliness or completeness of such information and assumes no responsibility for its use, or for infringement of any patent or other intellectual property rights of third parties that may result from its use. Silicon Standard reserves the right to make changes as it deems necessary to any products described herein for any reason, including without limitation enhancement in reliability, functionality or design. No license is granted, whether expressly or by implication, in relation to the use of any products described herein or to the use of any information provided herein, under any patent or other intellectual property rights of Silicon Standard Corporation or any third parties. 1/11/2005 Rev.2.10 www.SiliconStandard.com 12 of 12