SS6783A(G) Battery Charge Controller for Low Power Charging FEATURES DESCRIPTION Fast charge control of NiMH/NiCd batteries. Fast charge termination by: −∆V, 0 ∆V safety The SS6783A fast charge controller IC is designed for intelligent charging of NiMH or NiCd batteries without the risk of overcharge. timer, or maximum voltage. Protection against battery voltage faults. -D V detection (-0.25%) and 0D V detection (peak) Pulsed trickle-charge mode. voltage timer) are the primary methods employed Quick and easy testing for production. by the SS6783A to terminate fast charging. 8-pin DIP or SO packages. Fast charging can also be cut off using the maximum battery voltage along with the safety timer to prevent charging under fault conditions of APPLICATIONS the charging system or the battery itself. Battery Fast Chargers for: Mobile Phones. The safety timer period is adjustable for flexible Notebook and Laptop Personal Computers. usage allowing the SS6783A to be used with a wide Portable Power Tools and Toys. range of battery capacities. A test mode is provided Portable Communication Equipment. for charger manufacturers to dramatically reduce Portable Video & Stereo Equipment. production test time. This device is available with Pb-free lead finish (second-level interconnect) as SS6783AGS. TYPICAL APPLICATION CIRCUIT VIN=5V R3 10K D3 LL4148 2SC4672 R2 0.5 Q1 R1 680 + D1 D2 LL4148 LL4148 C1 47µF 2-Cell NiMH/NiCd R4 68K R5 220K R7 100K R6 100K C2 4.7µF C3 0.1µF R8 120K LED1 U1 1 REF VCC 8 2 TIMER VBT 7 R9 3 MODE ICON 6 200K 4 GND LED 5 R10 680 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 PIN CONFIGURATION SS6783AXXXX TOP VIEW Packing TR: Tape and reel (not for PDIP-8 (CN)) TB: Tubes REF 1 8 VCC 2 7 VBT MODE 3 6 ICON 4 5 LED TIMER Package type N: Plastic PDIP-8 (only available in tubes) S: Small outline SO-8 GND C: Commercial G: Commercial, Pb-free lead finish (Available for SO-8 (GS) only) Examples: SS6783ACSTR in SO-8 package, shipped on tape and reel SS6783AGSTR in SO-8 package with Pb-free lead finish, shipped on tape and reel 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 100k 2 3 RTIMER 100k 120k 4 REF VCC TIMER MODE GND VBT ICON LED 8 5V + 7 6 5 680 - VOLTAGE SOURCE 680 SS6783A RED GREEN 5V 1/11/2005 Rev.2.10 www.SiliconStandard.com 2 of 12 SS6783A(G) ELECTRICAL CHARACTERISTICS PARAMETER (TA=25°C, VCC=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 Battery Low During Initial Timer After Initial Timer VBT Battery High 1.1 mA 0.11 0.16 0.21 0.63 0.69 0.75 2.6 2.7 2.80 25 50 V LED, ICON Pins Output Impedance Input Impedance ON OFF MODE pin 1/11/2005 Rev.2.10 300 VBT pin Recommended External Resistor of TIMER pin −∆V Detection accuracy 1 kΩ 1 RTIMER VBT=2V www.SiliconStandard.com Ω MΩ MΩ 2 100 1000 kΩ -0.15 -0.25 -0.35 % 3 of 12 SS6783A(G) TYPICAL PERFORMANCE CHARACTERISTICS (TA=25°C, RTIMER=100kΩ, VCC=5V, refer to Test Circuit) 81.5 81.0 Safety Timer (min) Supply Current (mA) 1.08 1.02 0.96 0.90 80.5 80.0 79.5 79.0 78.5 0.84 4.4 4.6 4.8 5.0 5.2 78.0 4.4 5.4 4.6 4.8 VCC (V) 5.4 5.6 1.05 Supply Current (mA) Frequency (Hz) 4.4 4.2 4.0 3.8 3.6 4.4 4.6 4.8 5.0 5.2 5.4 1.00 0.95 0.90 0.85 0.80 0 5.6 20 40 60 80 Temperature (°C) VCC (V) Fig. 3 LED Flashing Frequency vs. Supply Voltage Fig. 4 Supply Current vs. Temperature 82 5.0 81 4.8 Frequency (Hz) Safety Timer (min) 5.2 Fig. 2 Safety Timer vs. Supply Voltage Fig. 1 Supply Current vs. Supply Voltage 80 79 78 77 76 75 5.0 VCC (V) 4.6 4.4 4.2 4.0 3.8 3.6 0 20 40 60 Temperature (°C) Fig. 5 Safety Timer vs. Temperature 1/11/2005 Rev.2.10 80 3.4 -20 0 20 40 Temperature (°C) 60 80 Fig. 6 LED Flashing Frequency vs. Temperature www.SiliconStandard.com 4 of 12 SS6783A(G) TYPICAL PERFORMANCE CHARACTERISTICS (Continued) 2.80 0.84 2.76 VBT (V) VBT (V) 0.80 2.72 2.68 0.72 0.68 2.64 2.60 0.76 0.64 0 20 40 60 80 0 60 80 33 Output Impedance (W ) 0.20 0.18 VBT (V) 40 Temperature (°C) Fig. 8 VBT (Low) Limit vs. Temperature (After Initial Timer) Temperature (°C) Fig. 7 VBT (High) Limit vs. Temperature 0.16 0.14 0.12 20 0 Fig. 9 1/11/2005 Rev.2.10 20 40 60 80 Temperature (°C) VBT (Low) Limit vs. Temperature (During Initial Timer) 30 27 24 21 0 20 40 60 80 Temperature (°C) Fig.10 Output Impedance vs. Temperature (LED, ICON Pins) www.SiliconStandard.com 5 of 12 SS6783A(G) BLOCK DIAGRAM MODE MODE Selection GND VCC TIMER Bandgap Reference & Voltage Regulator Oscillator LED Display Control Unit Charge Control REF Battery Voltage Protection Setting ICON State Machine 13-bit A/D Charge Control Unit Battery Voltage Protection VBT PIN DESCRIPTIONS PIN 1: REF- Reference voltage input, PIN 5: LED- acceptable voltage range : indicate the battery charging (VCC-1.4V) ~ (0.5VCC+0.4V) status. PIN 2: TIMER- Determining the period of PIN 6: ICON- Open-drain 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- 1/11/2005 Rev.2.10 Power ground. Divided battery voltage input to sense the battery voltage. operation for the SS6783A. PIN 4: GND- Open-drain output used to PIN 8: VCC- www.SiliconStandard.com Power supply input at 5V±10%. 6 of 12 SS6783A(G) APPLICATION INFORMATION OPERATION Power-On and Battery Pre-Qualifying -∆V Cutoff When power is first applied to the SS6783A, all The SS6783A makes a voltage sampling at VBT internal digital circuit blocks of the SS6783A are pin every 4 seconds when safety timer period is set reset by the internal power-on-reset circuitry and the equal to 80 minutes. If a negative delta voltage of output LED flashes 3 times to indicate the initiation of 0.25% compared to its peak value is detected at power-on. The internal control unit then examines VBT pin, the fast charge cycle is terminated. the battery condition through the VBT pin. 0∆V Cutoff The acceptable range of VBT pin is 0.16V to 2.7V. If If the battery voltage stays at its peak value or the voltage of VBT pin fails to fall within the decreases very slowly for the duration determined predetermined acceptable limits, the SS6783A by the peak voltage timer which is 6% of safety enters a charge-suspending mode, in which all the timer, the fast charge action is terminated. internal circuitry remains in reset state. Maximum Safety Timer Cutoff Fast Charge The maximum fast charge period is determined by After the battery passes fault checks, fast charging the safety timer, which is set by a resistor begins while the initial timer and safety timer of the SS6783A start counting. The functions of −∆V connected from TIMER pin to GND. Safety timer, −∆V , sampling rate will be longer if the resistor detection, peak voltage timer, and maximum battery value is larger. When the value of the resistor is voltage are, however, disabled temporarily until the 100kΩ, the safety timer period equals 80 minutes. initial timer period in the initial stage of a charge After the safety timer period is finished, the fast cycle elapses. The initial timer period is equal to charge action is terminated. 1/80 of the safety timer. Maximum Voltage Cutoff 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 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. encountered, which are explained below: Negative delta voltage ( −∆V ) Peak voltage timer ( 0 ∆V ) Maximum charge time Maximum battery voltage 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 DESIGN GUIDE table following shows the resistor values for some Battery Voltage Measurement of the commonly chosen safety timer periods. Also The SS6783A measures the battery voltage shown in the table are their corresponding oscillator through VBT pin, which is connected to the battery frequencies. positive terminal through a resistor-divider network, as shown in Fig. 11. 800 VBAT RTIMER (kΩ) 600 RA R5 VBT C6 0.1µF + C5 4.7µF RB 7 100k 400 200 SS6783A 0 0 100 200 300 400 500 Safety Timer (min.) Fig. 13 Safety Timer vs. RTIMER 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 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 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 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 0∆V is Detected LED Display Fast Charge (ICON OFF) Yes Yes No If -0.25% ∆V 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. 12 1/11/2005 Rev.2.10 Yes Function Flow Chart of SS6783A www.SiliconStandard.com 9 of 12 SS6783A(G) TABLE 2 OSC. Safety timer Freq.(kHz) (min.) 11 256 10 23 131 20 48 65.8 40 74 43.1 60 100 32.8 80 152 21.6 120 206 16.0 160 314 10.6 250 491 6.89 380 667 5.04 520 RTMR (kΩ) 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 LED 1Hz Fast Charge Fault Charging Completed Conditions 4Hz ON Flashing OFF Charging Current Control As shown in the typical application circuit, the Selecting Mode of Operation SS6783A offers an open-drain output at the ICON The SS6783A provides three modes of operation: pin, to control the charging current flow in fast normal, test, and AC mode determined by the charge state and switch on to inhibit the charging setting of MODE pin. The SS6783A will operate current flow in fault conditions. When fast charge is normally when the MODE pin is left floating (a completed, the SS6783A enters the trickle charge 0.1µF capacitor is recommended to be tied to mode. In trickle charge mode, the ICON pin output MODE pin if the charge circuit works in a noisy switches with 1/128 duty cycle. environment). When the MODE pin is biased to GND, the function of -∆V detection is disabled. Power Fast Charge Fault When the MODE pin is biased to VCC, the ON Charging Completed Conditions ON OFF 1/128 SS6783A enters the test mode. The test mode can ICON be used to significantly reduce production test time. ON Duty cycle TABLE 3 MODE pin Mode VCC Test Function Safety timer period scaled down to 1/32 Floating Normal GND AC 1/11/2005 Rev.2.10 Normal operation -∆V detection disabled www.SiliconStandard.com 10 of 12 SS6783A(G) APPLICATION EXAMPLE U1 VIN 11~15V C5 1µF 1N4148 D3 + 78L05 VIN VOUT GND + C6 10µF R1 U2 L1 R10 D1 SS24 R9 1 390K 2 3 C7 4 D4 U3 8 DC BOOST DE IS CF VCC 6 GND 470P FB 7 5 IN4148 C2 220µF D2 C3 0.1µF 1 REF R2 BAT1 **BATTERY + 120/0.25W 240K R11 100K R5 120K C4 0.1µF + C9 4.7µF C10 R12 47nF 150K VCC 2 TIMER VBT 3 MODE ICON 4 GND LED 8 R6 R7 7 680 47K R8 10K 6 5 Q1 MMBT2222A SS6783A RS 0.5/0.25W + **: 2~4 NiMH/NiCd cells C8 Note: Charge Current: 0.3V/Rs Ampere 220µF SS6563 RED SS24 220µH 1µF LED1 R4 120K 1K C1 R3 100K Safety Timer: 120 min Fig. 14 1/11/2005 Rev.2.10 Switching Battery Charger Circuit with Wide Input Voltage Range www.SiliconStandard.com 11 of 12 SS6783A(G) PHYSICAL DIMENSIONS (unit: mm) 8 LEAD PLASTIC SO (CS/GS 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 A H 5.80 6.20 L 0.40 1.27 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 A1 C B 8 LEAD PLASTIC DIP L (CN) D E1 E A2 A1 C L eB b 1.27(TYP) e e 2.54 (TYP) eB — 10.92 L 2.92 3.81 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