74LV4799D,112

INTEGRATED CIRCUITS 74LV4799 Timer for NiCd and NiMH chargers Product specification Supersedes data of 1998 Apr 07 IC24 Data Handbook
     1998 Apr 20 Philips Semiconductors Product specification Timer for NiCd and NiMH chargers 74LV4799 FEATURES DESCRIPTION • Wide supply voltage range of 0.9 V to 6 V allows 1 to 4-cell The 74LV4799 is a low-voltage Si-gate CMOS control IC for battery management. It consists of: applications • 17-stage divider • 10-stage up/down counter • Control logic • Integrated precision oscillator (using external timing components) • Automatic power-ON reset • Scan test facilities • Battery charging/full indication output (LED) • Battery-low indication output (MOLLI) • Open-drain-N outputs for driving the load transistor • 10 V allowed on special inputs • Supports virtually all battery chargers, including switched-mode power supplies • On-chip timer calculates the actual capacity of the battery by measuring the charger time, discharge time and self-discharge time • Automatic switch-over to trickle charge after completion of the charge time • Can be adjusted for use with different types of batteries: – Charge time: 4 to 16 hours – Discharge time: 15 minutes to 4.7 hours – Self-discharge time: 50 to 100 days Battery management with the 74LV4799 is based on the principle of time measurement. It measures the charge time, discharge time and self-discharge time by means of a very accurate on-chip oscillator, a divider and an up/down counter. • Battery status indication included: – LED output for charging/full indication – MOLLI output for battery-low indication • LED mode select allows two different methods of indication • Automatic power-ON reset • Low-power consumption • Requires only a few peripheral components • Very accurate on-chip oscillator • Scan test facilities included • ICC category: non-standard. PIN CONFIGURATION LED 1 16 VCC EN 2 15 SCI EN 3 14 SCAN Vin 4 13 IOSC PWRS 5 12 RS MOLLI/SCO 6 11 RD SEL 7 10 RC GND 8 9 DIS APPLICATIONS • Time-controlled NiCd and NiMH low-current chargers • Domestic appliances such as rechargeable battery shavers, electric toothbrushes etc. • Portable equipment such as notebook PCs, laptop PCs, camera flash units etc. • Personal communications like cordless telephones, personal SV01643 mobile radios, pagers, etc. QUICK REFERENCE DATA GND = 0V; Tamb = 25°C SYMBOL PARAMETER VCC CONDITIONS DC supply voltage TYPICAL TYPICAL TYPICAL UNIT 6.0 V 0.9 ICC Operating supply current VCC = 3.3V; self-discharge mode; Rs = 100 k; C1 = 220nF
f Oscillator frequency tolerance VCC = 1 to 6 V µA 36 7 % ORDERING INFORMATION PACKAGES TEMPERATURE RANGE OUTSIDE NORTH AMERICA NORTH AMERICA CODE 16-Pin Plastic DIL 0°C to +70°C 74LV4799 N 74LV4799 N SOT38-4 16-Pin Plastic SO 0°C to +70°C 74LV4799 D 74LV4799 D SOT109-1 16-Pin Plastic SSOP Type II 0°C to +70°C 74LV4799 DB 74LV4799 DB SOT338-1 16-Pin Plastic TSSOP Type I 0°C to +70°C 74LV4799 PW 74LV4799PW DH SOT403-1 1998 Apr 20 2 853-2058 19258 Philips Semiconductors Product specification Timer for NiCd and NiMH chargers 74LV4799 FUNCTIONAL DIAGRAM 4 7 9 5 14 15 EN EN SEL DIS PWRS SCAN SCI GND GND GND Vin POWER–ON RESET VCC CONTROL LOGIC GND GND MOLLI/SCO 3–STAGE CP DIVIDER 5–14 STAGE DIVIDER 2 3 10–STAGE UP/DOWN COUNTER 6 GND 13 IOSC OSCILLATOR CP LED GND RC 10 RD RS 11 12 SV01644 IEC LOGIC SYMBOL F BATT. TIMER 13 G U+[1] IOSC 12 2 RS 11 10 4 EN 3 SCO 6 RD RC 1 9 DIS 15 SCI 14 MOLLI SCAN/Z1 I=0 CT=0 5 U+[2] PWRS 0V 7 SEL LED 16 8 1 SV01645 1998 Apr 20 3 1 Philips Semiconductors Product specification Timer for NiCd and NiMH chargers 74LV4799 PIN DESCRIPTION PIN NO. SYMBOL NAME AND FUNCTION 1 LED LED driver output pin (active LOW) 2 EN Enable output (active HIGH) 3 EN Enable output (active LOW) 4 Vin External power input 5 PWRS Power sense input 6 MOLLI/SCO More-or-less-low-indication output (active LOW)/scan test output 7 SEL LED mode select input 8 GND Ground (0 V) 9 DIS Discharge input (active LOW) 10 RC External resistor pin 3-State oscillator output (charge) 11 RD External resistor pin 3-State output (discharge) 12 RS External resistor pin 3-State output (self-discharge) 13 IOSC Oscillator input 14 SCAN Scan test mode select input (active HIGH) 15 SCI Scan test input 16 VCC Positive supply voltage Power On Reset. An automatic Power On Reset initiates the IC when the battery is discharged and power is connected to the circuit. The initial condition is the charge mode in which the counter is reset and counts from zero up to maximum. At start up, the battery therefore always receives a full charge cycle. When a partially charged battery is inserted, it may be over-charged during the first cycle. To guard against this, simply replace the resistor at the RC pin with an NTC type which is in good thermal contact with the battery. If the temperature of the battery increases, the frequency of the oscillator also increases to quickly reach a counter full indication and switch-over to trickle charge. With a battery that is almost completely discharged, the POR input can also be activated during discharge or self-discharge. The counter will then be reset to zero. This is a correct action while returning to the initial condition. reaches its maximum value and the EN and EN outputs switch over from the continuous charge to the trickle charge mode. Trickle charge mode. At the maximum counter value, it is assumed that the battery is fully charged. The counter stops and remains on this maximum value. The EN and EN outputs switch over from the continues charge to the trickle charge mode. In the trickle charge mode, the average charge current is reduced to only compensate the self-discharge of the battery by using the dedicated duty cycle control. The control is dedicated because it adjusts the duty cycle in inverse proportion to the load current, resulting in a fixed charger current irrespective of the kind of charger (e.g. 4-hour or 16-hour charger). In the trickle charge mode, the oscillator circuitry alternately generates 4 periods of RC -C1 time-constant, and 3 periods of the RS -C1 time-constant (See Figure 1). Power-on sensing. Because this IC supports virtually all battery chargers, the PWRS input has a broad input frequency spectrum (active HIGH to 100 kHz). A pull-down circuit at the PWRS input allows detection of the open state which corresponds to an inactive charger. A HIGH level on the PWRS input, or an AC signal up to 100 kHz, enables the charge mode. Discharge mode. The discharge input (DIS) is used to detect the discharge of the battery. If DIS is LOW, the counter counts down. The clock frequency is determined by the external capacitor and resistor at the RD output. If PWRS is inactive (LOW or open), the EN output is LOW, and the EN output is in the high impedance OFF-state (no charge of the battery). This is called the discharge mode. If PWRS is active, the circuit is in the charge/discharge mode. Start-up with low battery voltage. Good start-up, even with an un-charged battery, is assured by using the VIN input. The voltage on the VIN input biases the external bipolar transistors at the EN or EN output, even if the IC is not yet functioning. After the battery has received sufficient charge, the internal control logic takes over control of the EN and EN outputs. Charge/Discharge mode. If DIS is LOW and PWRS is active (HIGH or pulsed), the circuit is in the charge/discharge mode. The counter counts down. The clock frequency is determined by the external capacitor and resistor tied at the RD output. The EN output is HIGH, and the EN output is LOW initiating continuous charge of the battery. The battery is therefore charged and discharged at the same instant, thereby maintaining a better load condition of the battery. Charge mode. This mode is selected when PWRS is active (HIGH or pulsed) and the discharge input DIS is HIGH. The EN output is HIGH, and the EN output is LOW initiating continuous charge of the battery. The counter then counts from the zero state up to the maximum value. The clock frequency is determined by the external capacitor and resistor connected to the RC output. The counter stops when it 1998 Apr 20 4 Philips Semiconductors Product specification Timer for NiCd and NiMH chargers 74LV4799 on. To prevent damaging the battery, an alarm signal on the LED output will alert the user to switch off the load. The alarm signal is easily recognized, because the LED output will blink at a higher frequency than normal (about 5 Hz instead of 1 Hz). This alarm indication is only active if the SEL input is HIGH or open. If the SEL input is LOW, no alarm indication is present, because in many applications simultaneous charging and discharging is quite acceptable. (See charge/discharge mode) Self-discharge mode. If DIS is HIGH and PWRS is inactive (LOW or open), the battery is being neither charged nor discharged. The circuit is in the self-discharge mode. This mode represents the battery leakage (self-discharge). The counter counts down. The clock frequency is determined by the external capacitor and resistor at the RS output. When the counter reaches the zero state, it stops. LED mode select. The LED output drives a battery status LED which indicates the charge/full status of the battery. For optimum flexibility, two modes of operation are built-in. • Mode 1: • Mode 2: Scan test mode. If the SCAN input (pin 14) is made active HIGH, the circuit is in the test mode. The tester clock is connected to the IOSC pin (pin 13). In the scan mode, the on–chip oscillator is bypassed to allow rapid testing of the divider/counter. The scan test patterns are available on request. The scan test data is entered serially through the SCI input (pin 15). The scan out data is present on the MOLLI/SCO output (pin 6), which then acts as a scan output. If SEL is LOW, the LED output is active LOW in the charge mode, and the LED blinks with a frequency of about 1 Hz during trickle charge. If SEL is HIGH or open, the LED output blinks with a frequency of about 0.25 Hz in the charge mode, and is active LOW during trickle charge. In the discharge or self-discharge mode, the LED output is open except when PWRS is active (HIGH or pulsed). Then, the battery is charging and discharging simultaneously. Although the discharge mode is dominant, the LED output is active when PWRS is also active. Remaining energy indication. The scan test facility can be used as a remaining energy indication because the value of the counter can be read out at the scan output (MOLLI/SCO). This is done by briefly interrupting the normal mode of operation, putting the circuit in the scan mode, and reading out the counter value. The circuit then reverts to the normal mode. This only works correctly with the MOLLI/SCO output and SCI input linked (round coupled loop) and with exactly 49 clock pulses applied to the IOSC input. NOTE: The blink frequency depends on the oscillator frequency. (See application information) Low indication. As part of the user interface, the MOLLI output shows when the battery needs to be charged. MOLLI stands for More Or Less Low Indication (active LOW). The function is as follows: In the discharge mode, (DIS is active LOW), the counter counts down and, when it reaches the zero state, it stops. If DIS is switched HIGH, the MOLLI output gives an output signal of four periods of about one second, with a 50% duty cycle. This can be used to activate a buzzer. The MOLLI output signal of four periods will be interrupted as soon as PWRS is activated. The serial scan-out data is available on the MOLLI/SCO output. The value of the counter can be decoded by reading the correct bits. Details are given later in the section “Application information”. Output drivers EN and EN. In one-cell battery (low-voltage) applications, the drive from the ENABLE output (EN) is insufficient to provide the base current directly for the external bipolar PNP regulator transistor. The inverse signal has therefore been made available at the ENABLE output (EN) to drive an extra bipolar NPN transistor that can provide the base current for the bipolar PNP regulator transistor as shown in Figure 2. Alarm indication. If an almost completely discharged battery is connected to the charger, it may not be noticed by the user if the load switch is still FUNCTION TABLE 1 OPERATING MODES INPUTS PWRS OUTPUTS VIN DIS EN EN H L RC Charge H or H H Trickle charge H or H H Charge/discharge H or H L H L Z RD RS Z Z Z Discharge L or open X L L Z Z Self-discharge L or open X H L Z Z 1998 Apr 20 DIVIDER/COUNTER 5 Z MODE Count up 22 sections VALUE < max Stop max Z Count down 18 sections ≥ min Z Count down 18 sections ≥ min Count down 27 sections ≥ min Philips Semiconductors Product specification Timer for NiCd and NiMH chargers 74LV4799 FUNCTION TABLE 2 STATUS INDICATION INPUTS OUTPUTS COUNTER DIS SEL(1) LED MOLLI H or H L L Z Count up < max H or H H or open Z Count up < max Charge/discharge H or L L L Z Count down ≥ min Trickle charge H or H or H H L H or open L Z Z Stop Stop max max PWRS MODE Charge VALUE Discharge L or open L X Z Z Count down > min Self-discharge L or open H X Z Z Count down > min Low L or open ↑ X Z Low ↑ ↑ X H or L H or open Alarm Z Stop Z(2) Z min Count up ≥ min Count down ≥ min NOTES: 1. Don’t change SEL during operation. 2. The MOLLI function will be interrupted as soon as PWRS is activated. H L Z X = = = = = = = = ↑ HIGH voltage level LOW voltage level high impedance OFF-state don’t care pulsed (H/L) pulsed (Z/L) 4 periods of about one second (Z/L) LOW-to-HIGH level transition Z–state R Z–state C Z–state R I Z–state S OSC EN Z–state EN Operation in the trickle charge mode. The duration of the RC cycle determines the duty cycle of the enable outputs (EN and EN), allowing a dedicated control. The average trickle charge current will compensate for the self-discharge, independent of the charge current. SV01646 Figure 1. Trickle charge mode characteristics. 1998 Apr 20 6 Philips Semiconductors Product specification Timer for NiCd and NiMH chargers 74LV4799 RECOMMENDED OPERATING CONDITIONS SYMBOL CONDITIONS MIN TYP MAX UNIT See Note 1 0.9 1.2 6 V VI Input voltage pins 4, 5, and 9 Input voltage pins 7, 13, 14, and 15 0 0 – – 10 VCC V VO Output voltage pins 10, 11, and 12 Output voltage pins 1, 2, 3, and 6 0 0 – – VCC 10 V +70 °C VCC Tamb PARAMETER DC supply voltage Operating ambient temperature range in free air See DC and AC characteristics per device Input rise and fall times pin 5 tr, tf Input rise and fall times pins 7, 14 and 15 VCC = 1.0V; VI = 1.0V VCC = 2.0V; VI = 2.0V VCC = 3.0V; VI = 4.5V VCC = 3.6V; VI = 6.0V Input rise and fall times pin 9 0 – – 10 ms – – – – – – – – 500 200 100 50 ns – – 2 µs NOTE: 1. Single sided input protection applied on pins 4, 5, and 9. ABSOLUTE MAXIMUM RATINGS2, 3 In accordance with the Absolute Maximum Rating System (IEC 134). Voltages are referenced to GND (ground = 0 V). SYMBOL PARAMETER VCC IIK VI CONDITIONS DC supply voltage MIN MAX UNIT –0.5 +7.0 V DC input diode current pins 4, 5 and 9 VI < –0.5 or VI > 12 V ±20 DC input diode current pins 7, 13, 14 and 15 VI < –0.5 or VI > VCC + 0.5 V +20 NON repetitive peak DC input diode current pin 9 VI > 10 V and t < 10
s; see note 1 10 mA DC input voltage range pins 4, 5 and 9 –0.5 +12 DC input voltage range pins 7, 13, 14 and 15 –0.5 VCC + 0.5 V V IOK DC output diode current pins 1, 2, 3 and 6 VO < –0.5 V –20 mA IO DC output sink current pins 1, 2, 3 and 6 VO > 0 V –25 mA IOK DC output diode current pins 10, 11 and 12 VO < –0.5 or VO > VCC + 0.5 V ±20 mA IO DC output sink or source current pins 10, 11 and 12 –0.5 V < VO < VCC + 0.5 V ±25 mA ±50 mA +150 °C IGND, ICC DC GND or VCC current Tstg Storage temperature range Ptot t t Power dissi dissipation ation per er package ackage Plastic DIL Plastic mini-pack (SO) Plastic Pl ti shrink h i k mini-pack i i k (SSOP and d TSSOP) –65 for temperature tem erature range: –40 40 to +125 °C C above + 70 °C derate linearly y with 12 mW/K above + 70 °C derate linearly with 8 mW/K above + 60 °C derate b d t linearly li l with ith 5.5 5 5 mW/K W/K 750 500 400 mW NOTES: 1. In applications where a motor is present, the input voltage may exceed the maximum VI, level of 10 V at the DIS input for a very short period when the motor is switched off. 2. Stresses beyond those listed may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these or any other conditions beyond those under “recommended operating conditions” is not implied. Exposure to absolute maximum rated conditions for extended periods may affect device reliability. 3. The input and output voltage ratings may be exceeded if the input and output current ratings are observed. 1998 Apr 20 7 Philips Semiconductors Product specification Timer for NiCd and NiMH chargers 74LV4799 DC ELECTRICAL CHARACTERISTICS Over recommended operating conditions. Voltages are referenced to GND (ground = 0 V). LIMITS SYMBOL VIH VIL VOH VOL PARAMETER HIGH level Input voltage LOW level Input voltage +25°C TEST CONDITIONS 0°C to +70°C MIN TYP MAX MIN MAX VCC = 1.0 V 0.8 0.5 – 0.8 – VCC = 4.5 V 3.6 2.4 – 3.6 – VCC = 6.0 V 4.8 3.2 – 4.8 – VCC = 1.0 V – 0.5 0.2 – 0.2 VCC = 4.5 V – 2.1 0.9 – 0.9 VCC = 6.0 V – 2.8 1.2 – 1.2 0.90 0.96 – 0.89 – VCC = 6.0 V; VI = VIH or VIL; IO = –6.1mA 5.73 5.84 – 5.66 – HIGH level output voltage; g RS output VCC = 1.0 V; VI = VIH or VIL; IO =–24µA 0.90 0.96 – 0.89 – VCC = 6.0 V; VI = VIH or VIL; IO =–760µA 5.73 5.84 – 5.66 – LOW level output voltage; g RC, RD outputs VCC = 1.0 V; VI = VIH or VIL; IO = 190µA – 0.04 0.10 – 0.11 VCC = 6.0 V; VI = VIH or VIL; IO = 6.1mA – 0.16 0.26 – 0.33 LOW level output voltage; g RS output VCC = 1.0 V; VI = VIH or VIL; IO =24µA – 0.04 0.10 – 0.11 VCC = 6.0 V; VI = VIH or VIL; IO =760µA – 0.16 0.26 – 0.33 LOW level output voltage; g MOLLI, LED outputs VCC = 1.0 V; VI = VIH or VIL; IO = 220µA – 0.04 0.10 – 0.11 VCC = 6.0 V; VI = VIH or VIL; IO = 7.4mA – 0.17 0.26 – 0.33 VCC = 1.0 V; VI = VIH or VIL; IO =360µA; pin 4 open – 0.04 0.10 – 0.11 VCC = 6.0 V; VI = VIH or VIL; IO =13.0mA; pin 4 open – 0.17 0.26 – 0.33 VCC = 1.3 V; VI = VIH or VIL; pin 4 = 10 V1 – 0.12 0.35 – 0.40 VCC = 1.0 V; VI = VIH or VIL; IO =140µA; pin 4 HIGH – 0.04 0.10 – 0.11 VCC = 6.0 V; VI = VIH or VIL; IO =5.0mA; pin 4 HIGH – 0.17 0.26 – 0.33 0.25 – – – 0.65 0.9 – – – – V µA LOW level output voltage; g EN output VCC POR level active inactive ICC Quiescent supply current VCC = 6.0 V; VI = VCC or GND; pins 5, 14, and 15 at GND; pins 7 and 9 at VCC2 – 34 50 – 400 Input leakage current pins 4 and 9 VCC = 1.0 V; VI = 10 V – – 500 – – Input leakage current pins 14 and15 VCC = 6.0 V; VI = VCC or GND – – 100 – – VCC = 1.0 V; VI = GND –0.5 –2.4 –10 – – VCC = 6.0 V; VI = GND –0.5 –2.4 –10 – – VCC = 1.0 V; VI = VCC 0.5 2.4 10 – – VCC = 6.0 V; VI = VCC 0.5 2.4 10 – – Pull-up current pin Pull-u in 7 Pull-down current pin in 5 IOZ V V nA OFF-state current pin 1, 3, and 6 VCC = 6.0 V; VI = VIH or V IL; VO = 10 V – – 500 – – OFF-state current pin 2 VCC = 6.0 V; VO = 6 V; Vin = open – – 100 – – OFF-state current pin 3 VCC = 6.0 V; VI = VIH or V IL; VO = 6 V – – 100 – – OFF-state current pins 10, 11, and 12 VCC = 6.0 V; VI = VIH or V IL; VO = VCC or GND – – ±100 – – NOTE: 1. This item guarantees that an external bipolar NPN-transistor can be switched off by the EN output. 2. Oscillator disabled. This can be done by IOC = HIGH or LOW. 1998 Apr 20 V VCC = 1.0 V; VI = VIH or VIL; IO = –190µA LOW level output voltage; g EN output IOZH V HIGH level output voltage; g RC, RD outputs LOW level output voltage; EN output II UNIT 8 µA nA nA Philips Semiconductors Product specification Timer for NiCd and NiMH chargers 74LV4799 AC CHARACTERISTICS GND = 0V; tr = tf ≤ 2.5ns; CL = 50pF SYMBOL Tamb (°C) TEST CONDITIONS PARAMETER +25 VCC(V) ∆f δLED Duty factor at pin in 1 δMOLLI Duty factor at pin in 6 MIN TYP MAX –11 –4 +3 –9 –2 +5 – 50 – 50 – 50 – 50 1.0 – 67 6.0 – 65 1.0 Oscillator frequency spread s read 0 to +70 Anyy resistor or capacitor according g to the application information, see note 1 6.0 1.0 See Note 2 6.0 1.0 See Note 3 6.0 MAX % % % tdeb d b Debounce suppression su ression at pin in 9 fi(max) i( ) Maximum frequency q y at power sense input 1.0 100 6.0 100 fi(min) i( i ) Minimum frequency q y at power sense input 1.0 50 6.0 50 NOTES: 1. The oscillator frequency can be calculated by: f  MIN UNIT ms kHz Hz 0.36 R
C1 2. During blinking. 3. An output signal of four periods will appear in case of discharged batteries and DIS is switched HIGH. APPLICATION INFORMATION Oscillator. The frequency will be determined by the external components RC, RD, RS, and C1. The frequencies can be calculated by the following expressions: f  0.36 ; f  0.36 ; f  0.36 . R S
C1 R C
C1 R D
C1 RC and C1 determine the charge time. RD and C1 determine the discharge time. RS and C1 determine the self-charge time. The charge, discharge and self-discharge times can be calculated as follows: 18 22 27 Charge time  2 ; Discharge time  2 ; Self-discharge time  2 fC fD fS In the trickle charge mode, the average charge current will be reduced by a factor: 1 3 x RS 1 4 x RC External components range SYMBOL VCC(V) RC/RD RS Resistor range Resistor range V1 1998 Apr 20 Capacitor Ca acitor range +25 OTHER MIN TYP UNIT MAX 1.0 5.360 100 2.0 1.150 100 C1 = 0.22 0 22 µF 4.5 0.562 100 6.0 0.511 100 1.0 42.20 825 9.09 825 4.22 825 3.32 825 2.0 C1 = 0.22 0 22 µF 4.5 6.0 C1 Tamb (°C) TEST CONDITIONS PARAMETER 1.0 no limit 2.0 no limit 4.5 no limit 6.0 no limit 9 k
k
k
k
pF F pF F Philips Semiconductors Product specification Timer for NiCd and NiMH chargers 74LV4799 Charge discharge times TIME RANGE PARAMETER Charge time 4 hours to 16 hours Discharge time 15 minutes to to 4.7 hours Self-discharge time 50 days to 100 days CONDITIONS Components ranges are within the values External com onents range given in Section “External components range” LED frequency The frequency of the LED output (pin1) is determined by the oscillator frequency. Three modes of operation, each with its own frequency, are possible. Mode SEL LED frequency Charge H or open fC 256 Trickle charge L Alarm H 1 8
f6 f C S fD 32 the Ron of the push–pull stage will contribute to the frequency spread. When high–value resistors are used, any possible output leakage of the not–selected 3–State outputs will cause a frequency deviation. For these reasons, the resistor values must be within the specified ranges. MOLLI pulse duration The MOLLI output gives an output signal of four periods with a 50% duty cycle. The duration of one period is determined by: 16/fs Timing accuracy. The timing accuracy depends on the accuracy of the on–chip oscillator and on the external R and C components. The inaccuracy of the on–chip oscillator is specified as maximum +/–7%. In most cases the actual inaccuracy will be significantly lower. This depends on the supply voltage as well as the value of the external components. Influence of supply voltage The trip levels of the oscillator are fixed at 20% and 80% of Vcc. At higher supply voltages the spread of the trip levels decreases in greater proportion because the offset voltage remains constant, and the propagation delay decreases. Furthermore, the Ron values of the push–pull driving stage decrease at higher voltages. Influence of Resistor value. Low resistor values cause some spread because the RC combination is biased by a 3–State push–pull output. The spread of SPREAD-CAUSING FACTORS SYMBOL Voffff tP RON RON RON RON 1998 Apr 20 VCC (V) PARAMETER Offset voltage Propagation Pro agation delay outputs P-channel resistance RC, RD out uts N-channel resistance RC, RD out outputs uts P-channel resistance RS out output ut N-channel resistance RS out output ut 10 Tamb (°C) MIN TYP MAX UNIT 1.0 7 mV 6.0 7 mV 1.0 22 ms 6.0 5.5 ms 1.0 170 W 6.0 25 W 1.0 250 W 6.0 35 W 1.0 1300 W 6.0 180 W 1.0 1300 W 6.0 180 W Philips Semiconductors Product specification Timer for NiCd and NiMH chargers 74LV4799 at the DIS input. The circuitry allows a switch de–bounce time of max. 10 ms. Error free operation, even under extreme conditions. Several measures are taken in the circuit design to ensure error–free operation, even with very low supply voltages. Moreover, the circuit has been made very insensitive to the effects of external fields. The measures taken during the design are: Schmitt trigger on PWRS (power sense) input. The PWRS input can be corrupted by high transients due to disturbances on the mains supply. To suppress any false triggering, the PWRS input is provided with a Schmitt–trigger. However, for some applications, it is advisable to connect a low–value capacitor (150 pF min.) between the PWRS input and GND. • Use of synchronous logic • Bistable POR instead of monostable POR • Data retention assured below a supply voltage of 0.9 V. • Debounce circuitry on DIS input (maximum expected debounce Special oscillator security to prevent any malfunction. The excellent performance of the oscillator is achieved by using linear op–amp techniques. The oscillator consists of an internal reference, two comparators and a latch. Care was taken to design a very reliable oscillator even with a supply voltage below 0.9 V. If one of the comparators ceases to operate with a supply voltage below 0.9 V, the latch will not be corrupted. Priority was given to stop the oscillator rather than allow uncontrolled oscillation. time = 10 ms) • Schmitt trigger on PWRS (power sense) input and on DIS input • Special oscillator security to prevent any malfunction. Synchronous logic and bistable POR. Use of synchronous logic results in much lower sensitivity to spikes on input pins. The POR is adapted to fit well into a synchronous environment. An increasing supply voltage sets the POR. The POR output signal is routed to the control logic and divider/counter. it is synchronized with the on–chip clock. After all flip–flops are reset, a reset acknowledge signal is generated which resets the POR. This method ensures that the POR signal is acknowledged in all cases, even at very low voltages. All these measures result in reliable 1-cell to 4-cell battery charge management. Remaining energy indication: The scan test facility can be used as a remaining energy indication because the value of the counter can be read–out at the scan output (MOLLI/SCO). This is achieved by briefly interrupting the normal mode of operation, putting the circuit in the scan mode (pin 14 = HIGH), and reading–out of the counter value. The circuit is then returned to the normal mode (pin 14 = LOW or open). Data retention. The circuit may be used in an application where an electric motor is present. When the motor is switched on, it will disturb the supply voltage for a short period. The POR level is set at such a level that, even with very low supply voltages, the POR will not respond during motor switch on. The flip–flops will retain their data during the supply voltage disturbance because of the inherent data retention of any CMOS gate. However, when the battery is almost completely discharged and the motor switch is activated, the dip on the supply voltage line can be too large. The retention of the POR is therefore made deliberately worse than that of the internal flip–fops. The POR will therefore respond long before the flip–flops will loose their data. This results in a proper start condition for a new charge cycle. Read–out procedure: The contents of the counter flip–flops can be read–out in the scan mode. To ensure that there is no disturbance of the circuit function, it is essential to either create a round coupled loop by linking the MOLLI/SCO output (pin 6) directly to the SCI input pin 15), or to shift–in the serial data of the scan line at the SCI input after completion of the read out cycle. 49 clock pulses are needed on the Iosc input (pin 13) to shift–out the contents of the whole scan line. The most–significant bit of the counter will appear at the MOLLI/SCO output after the last clock pulse. The least–significant bit after the penultimate clock pulse, etc. Selecting the last three or four bits will yield sufficiently high accuracy to obtain the counter value which represents the remaining energy of the battery. Debounce circuitry on DIS input. A discharge cycle is activated by a switch. To protect the circuit from any bounce of the switch contacts, de–bounce circuitry is provided BYD13D BYD13D BC327/ BC636 n.c. 4 BC557 1 220 V V in BZD23 110 V BZD23 BC547 EN EN LED 2 LOAD 5 AC mains RZ 3 V CC PWRS 74LV4799 7 SEL MOLLI 14 SCAN 15 SCI DIS RC RD R S I OSC 10 11 12 13 16 BC557 6 battery 9 8 buzzer BYD13D BYD13D SV01647 Figure 2. Typical application of the low-voltage 74LV4799. 1998 Apr 20 11 Philips Semiconductors Product specification Timer for NiCd and NiMH chargers 74LV4799 1.0 mH TR1 33E 1 6 7 8 9 10 2µ2 2µ2 100–240 VAC 12/24 VDC Vin DRN VAC2 SRC 20 16 VAT VAC1 15 VIC PWR/LED C 16 TR1 13 S2 3 5 4 PWRS Vin 1 LED LOAD 74LV4799 EN DIS 11 GND 9 RC RD RS IOSC SEL GND 10 11 12 13 7 8 TEA1400 1µF VCC 12 S1 EN 10µ 14 S 1µF 1E SV01648 Figure 3. Application diagram of the 74LV4799 in combination with the high-voltage IC TEA1400. Q1 1 4 BYD13D LED V in A 3 RZ Z1 EN 5 LOAD PWRS 7 BYD13D 14 15 74LV4799 SEL EN 2 Q2 SCAN battery SCI RC 10 B RD 11 R S I OSC 12 13 MOLLI/ SCO 6 DIS GND 8 9 V CC 16 LS Option A: At V CC > 2.0 V Q1 may be directly biased by EN Option B: At V CC < 2.0 V add an extra NPN transistor (Q2) Figure 4. Inductive loader, showing the two options A and B. 1998 Apr 20 12 SV01649 Philips Semiconductors Product specification Timer for NiCd and NiMH chargers 74LV4799 DIP16: plastic dual in-line package; 16 leads (300 mil) 1998 Apr 20 13 SOT38-4 Philips Semiconductors Product specification Timer for NiCd and NiMH chargers 74LV4799 SO16: plastic small outline package; 16 leads; body width 3.9 mm 1998 Apr 20 14 SOT109-1 Philips Semiconductors Product specification Timer for NiCd and NiMH chargers 74LV4799 SSOP16: plastic shrink small outline package; 16 leads; body width 5.3 mm 1998 Apr 20 15 SOT338-1 Philips Semiconductors Product specification Timer for NiCd and NiMH chargers 74LV4799 TSSOP16: plastic thin shrink small outline package; 16 leads; body width 4.4 mm 1998 Apr 20 16 SOT403-1 Philips Semiconductors Product specification Timer for NiCd and NiMH chargers 74LV4799 NOTES 1998 Apr 20 17 Philips Semiconductors Product specification Timer for NiCd and NiMH chargers 74LV4799 Data sheet status Data sheet status Product status Definition [1] Objective specification Development This data sheet contains the design target or goal specifications for product development. Specification may change in any manner without notice. Preliminary specification Qualification This data sheet contains preliminary data, and supplementary data will be published at a later date. Philips Semiconductors reserves the right to make chages at any time without notice in order to improve design and supply the best possible product. Product specification Production This data sheet contains final specifications. Philips Semiconductors reserves the right to make changes at any time without notice in order to improve design and supply the best possible product. [1] Please consult the most recently issued datasheet before initiating or completing a design. Definitions Short-form specification — The data in a short-form specification is extracted from a full data sheet with the same type number and title. For detailed information see the relevant data sheet or data handbook. Limiting values definition — Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 134). Stress above one or more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation of the device at these or at any other conditions above those given in the Characteristics sections of the specification is not implied. Exposure to limiting values for extended periods may affect device reliability. Application information — Applications that are described herein for any of these products are for illustrative purposes only. Philips Semiconductors make no representation or warranty that such applications will be suitable for the specified use without further testing or modification. Disclaimers Life support — These products are not designed for use in life support appliances, devices or systems where malfunction of these products can reasonably be expected to result in personal injury. Philips Semiconductors customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify Philips Semiconductors for any damages resulting from such application. Right to make changes — Philips Semiconductors reserves the right to make changes, without notice, in the products, including circuits, standard cells, and/or software, described or contained herein in order to improve design and/or performance. Philips Semiconductors assumes no responsibility or liability for the use of any of these products, conveys no license or title under any patent, copyright, or mask work right to these products, and makes no representations or warranties that these products are free from patent, copyright, or mask work right infringement, unless otherwise specified.  Copyright Philips Electronics North America Corporation 1998 All rights reserved. Printed in U.S.A. Philips Semiconductors 811 East Arques Avenue P.O. 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     yyyy mmm dd 18 Date of release: 05-96 9397-750-04664