MAX712 ,NiCd/NiMH Battery Fast-Charge ControllersApplicationsMAX712EPE -40°C to +85°C 16 Plastic DIPBattery-Powered EquipmentMAX712ESE -40°C to +85° ..
MAX7129CPL ,4-1/2 Digit Single-Chip A/D Converter with LCD DriverELECTRICAL CHARACTERISTICS (MAX7129)
(V' to V" = 9V. VRE; :1.00V.TA = +25°C, tcus a 120kHz, unle ..
MAX7129CPL ,4-1/2 Digit Single-Chip A/D Converter with LCD Driverapplications involve the measurement ICL7129ACJL‘ (rc to +70%: 40 Lead CERDIP -
and display of ana ..
MAX7129CPL ,4-1/2 Digit Single-Chip A/D Converter with LCD Driverfeatures high impe-
dance differential inputs, excellent differential linearity,
true ratiometric ..
MAX7129CQH ,4-1/2 Digit Single-Chip A/D Converter with LCD DriverGeneral Description
The Maxim |CL7129A/MAX7129 is a high precision
monolithic 4-1/2 digit A/D c ..
MAX712CPE ,NiCd/NiMH Battery Fast-Charge ControllersGeneral Description ________
MB47358 ,DUAL OPERATIONAL AMPLIFIERFUJITSU SEMICONDUCTORDS04-11104-3EDATA SHEETLINEAR ICDUAL OPERATIONAL AMPLIFIERMB47358DUAL OPERATIO ..
MB47393 ,DUAL COMPARATORFUJITSU SEMICONDUCTORDS04-12103-4EDATA SHEETASSPDUAL COMPARATORMB47393n DESCRIPTIONThe Fujitsu MB47 ..
MB47393P ,Dual comparatorFUJITSU SEMICONDUCTORDS04-12103-4EDATA SHEETASSPDUAL COMPARATORMB47393n DESCRIPTIONThe Fujitsu MB47 ..
MB47393P ,Dual comparatorFUJITSU SEMICONDUCTORDS04-12103-4EDATA SHEETASSPDUAL COMPARATORMB47393n DESCRIPTIONThe Fujitsu MB47 ..
MB47393PF ,Dual comparatorFUJITSU SEMICONDUCTORDS04-12103-4EDATA SHEETASSPDUAL COMPARATORMB47393n DESCRIPTIONThe Fujitsu MB47 ..
MB4752A ,SUBSCRIBER LINE INTERFACE IC" mm;
gr T$544-A874
'j?itl,'l,lllill,ililill MB4752A April 1987
'llllllllllllllllllllllllill ..
MAX712
NiCd/NiMH Battery Fast-Charge Controllers
MAX712/MAX713
NiCd/NiMH Battery
Fast-Charge ControllersEVALUATION KIT AVAILABLE
General DescriptionThe MAX712/MAX713 fast-charge Nickel Metal Hydride
(NiMH) and Nickel Cadmium (NiCd) batteries from a DC
source at least 1.5V higher than the maximum battery
voltage. 1 to 16 series cells can be charged at rates up
to 4C. A voltage-slope detecting analog-to-digital convert-
er, timer, and temperature window comparatordetermine
charge completion. The MAX712/MAX713 are powered
by the DC source via an on-board +5V shunt regulator.
They draw a maximum of 5µA from the battery when not
charging. A low-side current-sense resistor allows the
battery charge current to be regulated while still
supplying power to the battery’s load.
The MAX712 terminates fast charge by detecting zero
voltage slope, while the MAX713 uses a negative
voltage-slope detection scheme. Both parts come in 16-
pin DIP and SO packages. An external power PNP tran-
sistor, blocking diode, three resistors, and three
capacitors are the only required external components.
The evaluation kit is available: Order the MAX712EVKIT-
DIP for quick evaluation of the linear charger.
________________________ApplicationsBattery-Powered Equipment
Laptop, Notebook, and Palmtop Computers
Handy-Terminals
Cellular Phones
Portable Consumer Products
Portable Stereos
Cordless Phones
FeaturesFast-Charge NiMH or NiCd BatteriesVoltage Slope, Temperature, and Timer
Fast-Charge CutoffCharge 1 to 16 Series CellsSupply Battery’s Load While Charging
(Linear Mode)Fast Charge from C/4 to 4C RateC/16 Trickle-Charge RateAutomatically Switch from Fast to Trickle ChargeLinear Mode Power Control5µA (max) Drain on Battery when Not Charging5V Shunt Regulator Powers External LogicMAX712
MAX713
THI
150Ω
68kΩ
22kΩ
10µF
0.01µF
1µF
10µF
0.01µF
DRV
2N6109DC IN
WALL
CUBE
1N4001
BATTERY
RSENSE
VLIMITBATT+
REF
TEMP
BATT-TLOGNDCC
LOAD
Typical Operating CircuitREF
DRV
GND
BATT-
PGM3
PGM2
VLIMIT
BATT+
PGM0
PGM1
THI
TLO
TEMP
FASTCHG
TOP VIEW
MAX712
MAX713
Pin Configuration
PART
MAX712CPEMAX712CSE
MAX712C/D0°C to +70°C
0°C to +70°C
0°C to +70°C
TEMP RANGEPIN-PACKAGE16 Plastic DIP
16 Narrow SO
Dice*
Ordering Information
Ordering Information continued at end of data sheet.*Contact factory for dice specifications.
**Contact factory for availability and processing to MIL-STD-883.
MAX712EPE
MAX712ESE
MAX712MJE-55°C to +125°C
-40°C to +85°C
-40°C to +85°C16 Plastic DIP
16 Narrow SO
16 CERDIP**
MAX712/MAX713
NiCd/NiMH Battery
Fast-Charge Controllers
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(IV+= 10mA, TA= TMINto TMAX, unless otherwise noted. Refer to the Typical Operating Circuit. All measurements are with respect to
BATT-, not GND.)
Stresses beyond those listed under “Absolute Maximum Ratings” 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 indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
V+ to BATT-.................................................................-0.3V, +7V
BATT- to GND........................................................................±1V
BATT+ to BATT-
Power Not Applied............................................................±20V
With Power Applied................................The higher of ±20V or
±2V x (programmed cells)
DRV to GND..............................................................-0.3V, +20V
FASTCHGto BATT-...................................................-0.3V, +12V
All Other Pins to GND......................................-0.3V, (V+ + 0.3V)
V+ Current.........................................................................100mA
DRV Current......................................................................100mA
REF Current.........................................................................10mA
Continuous Power Dissipation (TA= +70°C)
Plastic DIP (derate 10.53mW/°C above +70°C............842mW
Narrow SO (derate 8.70mW/°C above +70°C.............696mW
CERDIP (derate 10.00mW/°C above +70°C................800mW
Operating Temperature Ranges
MAX71_C_E .......................................................0°C to +70°C
MAX71_E_E....................................................-40°C to +85°C
MAX71_MJE.................................................-55°C to +125°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s).................................+300°C
VDRV= 10V
V+ = 0V, BATT+ = 17V
PGM3 = BATT-
5mA < IV+< 20mA
PGM3 = REF
PGM3 = open
PGM3 = V+
0V < TEMP < 2V, TEMP voltage rising
VLIMIT= V+
Per cell
PGM0 = PGM1 = BATT-, BATT+ = 30V
1.2V < VLIMIT< 2.5V, 5mA < IDRV< 20mA,
PGM0 = PGM1 = V+
0mA < IREF< 1mA
CONDITIONS30DRV Sink Current-1.51.5Battery-Voltage to Cell-Voltage
Divider Accuracy-1515Timer Accuracy
Trickle-Charge VSENSE12.015.620.0
1.53.97.0225250275Fast-Charge VSENSE1.61.651.7Internal Cell Voltage Limit-3030VLIMIT Accuracy-11THI, TLO, TEMP, VLIMIT Input Bias Current5BATT+ Leakage5IV+(Note 1)4.55.5V+ Voltage-1010THI, TLO Offset Voltage (Note 2)02THI, TLO, TEMP Input Range1.252.50External VLIMIT Input Range0.350.50Undervoltage Lockout30BATT+ Resistance with Power On0.5C1 Capacitance5C2 Capacitance1.962.04REF Voltage
UNITSMINTYPMAXPARAMETERMAX712
MAX713mV/tA
per cell0Voltage-Slope Sensitivity (Note 3)-2.5
MAX712/MAX713
NiCd/NiMH Battery
Fast-Charge Controllers
ELECTRICAL CHARACTERISTICS (continued)(IV+ = 10mA, TA= TMINto TMAX, unless otherwise noted. Refer to the Typical Operating Circuit. All measurements are with respect to
BATT-, not GND.)
Note 1:The MAX712/MAX713 are powered from the V+ pin. Since V+ shunt regulates to +5V, R1 must be small enough to allow at
least 5mA of current into the V+ pin.
Note 2:Offset voltage of THI and TLO comparators referred to TEMP.
Note 3:tAis the A/D sampling interval (Table 3).
Note 4:This specification can be violated when attempting to charge more or fewer cells than the number programmed. To ensure
proper voltage-slope fast-charge termination, the (maximum battery voltage) ÷(number of cells programmed) must fall
within the A/D input range.
Battery voltage ÷number of cells programmed
VFASTCHG= 10V
VFASTCHG= 0.4V
CONDITIONS1.41.9A/D Input Range (Note 4)10FASTCHGHigh Current2FASTCHGLow Current
UNITSMINTYPMAXPARAMETER
Typical Operating Characteristics(TA = +25°C, unless otherwise noted.)100k1M10k10M
CURRENT-SENSE AMPLIFIER
FREQUENCY RESPONSE (with 15pF)FREQUENCY (Hz)
GAIN (dB)
PHASE (DEGREES)
C2 = 15pF
FASTCHG = 0V
VOUTVIN
CURRENT-
SENSE
AMP
BATT-
BATT-
GND-+
MAX712/13 toc0120
-201k
CURRENT-SENSE AMPLIFIER
FREQUENCY RESPONSE (with 10nF)FREQUENCY (Hz)
GAIN (dB)
PHASE (DEGREES)
10010k
C2 = 10nF
FASTCHG = 0V
MAX712/13 toc02
CURRENT ERROR-AMPLIFIER
TRANSCONDUCTANCE
VOLTAGE ON CC PIN (V)
DRV PIN SINK CURRENT(mA)
FASTCHG = 0V, V+ = 5V
MAX712/13 toc03
SHUNT-REGULATOR VOLTAGE
vs. CURRENT
CURRENT INTO V+ PIN (mA)
V+ VOLTAGE (V)
DRV NOT SINKING CURRENT
DRV SINKING CURRENT
MAX712/13 toc04
ALPHA SENSORS PART No. 14A1002
STEINHART-HART INTERPOLATION
BATTERY TEMPERATURE(°C)
TEMP PIN VOLTAGE (V)
BATTERY THERMISTOR RESISTANCE (k
MAX712/13 toc05
Typical Operating Characteristics (continued)(TA = +25°C, unless otherwise noted.)
MAX713
NiMH BATTERY CHARGING
CHARACTERISTICS AT C RATECHARGE TIME (MINUTES)
MAX712/13 toc07CUTOFF
CELL VOLTAGE (V)
CELL TEMPERATURE (
MAX713
NiMH BATTERY CHARGING
CHARACTERISTICS AT C/2 RATE
1.45CUTOFF
CHARGE TIME (MINUTES)
CELL VOLTAGE (V)
CELL TEMPERATURE (
MAX712/13 toc09
MAX713
NiCd BATTERY-CHARGING
CHARACTERISTICS AT C/2 RATE
CHARGE TIME (MINUTES)
CELL VOLTAGE (V)
CELL TEMPERATURE (1.50150100CUTOFF
MAX712/13 toc0820
MAX713
CHARGING CHARACTERISTICS OF A
FULLY-CHARGED NiMH BATTERYCELL VOLTAGE (V)
CELL TEMPERATURE (
1.50CUTOFF
5 MINUTE REST
BETWEEN CHARGES
MAX712/13 toc10
MAX713
CHARGING CHARACTERISTICS OF A
FULLY CHARGED NiMH BATTERY
CELL VOLTAGE (V)
CELL TEMPERATURE (
5-HOUR REST
BETWEEN CHARGESCUTOFF
MAX712/13 toc11
MAX712/MAX713
NiCd/NiMH Battery
Fast-Charge Controllers
MAX713
NiCd BATTERY CHARGING
CHARACTERISTICS AT C RATECHARGE TIME (MINUTES)
CELL VOLTAGE (V)
CELL TEMPERATURE (
°C)
1.45CUTOFF
MAX712/13 toc06
Pin Description
MAX712/MAX713
NiCd/NiMH Battery
Fast-Charge ControllersCompensation input for constant current regulation loopCC11
Negative terminal of batteryBATT-12
GND13
Current sink for driving the external PNP current sourceDRV14
Shunt regulator. The voltage on V+ is regulated to +5V with respect to BATT-, and the shunt current
powers the MAX712/MAX713.V+15
Trip point for the under-temperature comparator. If the MAX712/MAX713 power on with the voltage-
on TEMP less than TLO, fast charge is inhibited and will not start until TEMP rises above TLO.TLO6
Sense input for temperature-dependent voltage from thermistors.TEMP7
Open-drain, fast-charge status output. While the MAX712/MAX713 fast charge the battery, FASTCHG
sinks current. When charge ends and trickle charge begins, FASTCHGstops sinking current.FASTCHG8
PGM2 and PGM3 set the maximum time allowed for fast charging. Timeouts from 33 minutes to 264
minutes can be set by connecting to any of V+, REF, or BATT-, or by leaving the pin unconnected
(Table 3). PGM3 also sets the fast-charge to trickle-charge current ratio (Table 5).
PGM2,
PGM39, 10
Trip point for the over-temperature comparator. If the voltage-on TEMP rises above THI, fast charge ends.THI5
PGM0 and PGM1 set the number of series cells to be charged. The number of cells can be set from
1 to 16 by connecting PGM0 and PGM1 to any of V+, REF, or BATT-, or by leaving the pin unconnected
(Table 2). For cell counts greater than 11, see the Linear-Mode, High Series Cell Countsection.
Charging more or fewer cells than the number programmed may inhibit ΔV fast-charge termination.
PGM0,
PGM13, 4
PINPositive terminal of batteryBATT+2
Sets the maximum cell voltage. The battery terminal voltage (BATT+ - BATT-) will not exceed VLIMIT x
(number of cells). Do not allow VLIMIT to exceed 2.5V. Connect VLIMIT to VREF for normal operation.
Alternatively, connect VLIMIT to V+ to set the maximum cell voltage to an internally preset 1.65V/cell.
VLIMIT1
FUNCTIONNAME2V reference outputREF16
System ground. The resistor placed between BATT- and GND monitors the current into the battery.
MAX712/MAX713
NiCd/NiMH Battery
Fast-Charge Controllers
Getting StartedThe MAX712/MAX713 are simple to use. A complete
linear-mode fast-charge circuit can be designed in a
few easy steps. A linear-mode design uses the fewest
components and supplies a load while charging.Follow the battery manufacturer’s recommendations
on maximum charge currents and charge-termination
methods for the specific batteries in your application.
Table 1 provides general guidelines. Decide on a charge rate (Tables 3 and 5). The slow-
est fast-charge rate for the MAX712/MAX713 is C/4,
because the maximum fast-charge timeout period is
264 minutes. A C/3 rate charges the battery in about
three hours. The current in mA required to charge at
this rate is calculated as follows:
IFAST= (capacity of battery in mAh)–––––––––––––––––––––––––(charge time in hours)
Depending on the battery, charging efficiency can be
as low as 80%, so a C/3 fast charge could take 3 hours
and 45 minutes. This reflects the efficiency with which
electrical energy is converted to chemical energy within
the battery, and is not the same as the power-
conversion efficiency of the MAX712/MAX713. Decide on the number of cells to be charged (Table 2).
If your battery stack exceeds 11 cells, see the Linear-
Mode High Series Cell Countsection. Whenever
changing the number of cells to be charged, PGM0
and PGM1 must be adjusted accordingly. Attempting
to charge more or fewer cells than the number pro-
grammed can disable the voltage-slope fast-charge
termination circuitry. The internal ADC’s input volt-
age range is limited to between 1.4V and 1.9V (see
the Electrical Characteristics), and is equal to the
voltage across the battery divided by the number of
cells programmed (using PGM0 and PGM1, as in
Table 2). When the ADC’s input voltage falls out of
its specified range, the voltage-slope termination cir-
cuitry can be disabled. Choose an external DC power source (e.g., wall
cube). Its minimum output voltage (including ripple)
must be greater than 6V and at least 1.5V higher
than the maximum battery voltage while charging.
This specification is critical because normal fast-
charge termination is ensured only if this require-
ment is maintained (see Powering the
MAX712/MAX713 section for more details). For linear-mode designs, calculate the worst-case
power dissipation of the power PNP and diode (Q1
and D1 in the Typical Operating Circuit) in watts,
using the following formula:
PDPNP= (maximum wall-cube voltage under
load - minimum battery voltage) x (charge current
in amps)Limit current into V+ to between 5mA and 20mA. For a
fixed or narrow-range input voltage, choose R1 in the
Typical Operation Circuitusing the following formula:
R1 = (minimum wall-cube voltage - 5V)/5mAChoose RSENSEusing the following formula:
RSENSE = 0.25V/(IFAST)Consult Tables 2 and 3 to set pin-straps before
applying power. For example, to fast charge at a
rate of C/2, set the timeout to between 1.5x or 2x the
charge period, three or four hours, respectively.
Table 1. Fast-Charge Termination Methods
Charge
RateNiMH BatteriesNiCd BatteriesΔV/Δt and/or
temperature, MAX713
ΔV/Δt and
temperature,
MAX712 or MAX713
> 2C
2C to C/2ΔV/Δt and/or
temperature,
MAX712 or MAX713
ΔV/Δt and/or
temperature, MAX713
ΔV/Δt and/or
temperature, MAX713ΔV/Δt and/or
temperature, MAX712 < C/2
MAX712/MAX713
NiCd/NiMH Battery
Fast-Charge Controllers
Table 2. Programming the Number
of Cells
Table 3. Programming the Maximum
Charge TimeCONTROL LOGIC
+5V SHUNT
REGULATOR
TIMER
PGM2PGM3
BATT-
BATT-
UNDER_VOLTAGE
BATT-
DRV
REF
100kΩ
100kΩ
HOT
ΔV_DETECT
TIMED_OUT
BATT-
FASTCHG
GND
BATT-
GND
CELL_VOLTAGE
INTERNAL IMPEDANCE OF PGM0–PGM3 PINS
FAST_CHARGE
POWER_ON_RESET
IN_REGULATION
VLIMIT
BATT+
PGM0
PGM1
PGM2
PGM3
PGMx
THI
TEMP
TLO
DETECTION
TEMPERATURE
COMPARATORS
CURRENT
AND
VOLTAGE
REGULATOR
COLD
0.4V
MAX712
MAX713
Figure 1. Block Diagram
PGM1
CONNECTION
PGM0
CONNECTIONV+V+
NUMBER
OF CELLSOpenV+BATT-V+REFV+OpenOpenV+OpenBATT-OpenREFOpenOpenREFV+REFBATT-REFREFREFOpenBATT-V+BATT-BATT-BATT-REFBATT-V+REF
PGM3
CONN
PGM2
CONNV+OpenV+BATT-
TIMEOUT
(min)V+V+OpenREFOpenOpenOpenBATT-OpenV+REFREFREFOpen
132REFBATT-
132REFV+
180BATT-REF
180BATT-Open
264BATT-BATT-
264BATT-V+
A/D
SAMPLING
INTERVAL
(s) (tA)Enabled
Disabled
Enabled
VOLTAGE-
SLOPE
TERMINATIONDisabled
Enabled
Disabled
Enabled
Disabled
Enabled
Disabled
Enabled
Disabled
Enabled
Disabled
Enabled
Disabled
MAX712/MAX713
NiCd/NiMH Battery
Fast-Charge Controllers
Detailed DescriptionThe MAX712/MAX713 fast charge NiMH or NiCd batter-
ies by forcing a constant current into the battery. The
MAX712/MAX713 are always in one of two states: fast
charge or trickle charge. During fast charge, the
current level is high; once full charge is detected, the
current reduces to trickle charge. The device monitors
three variables to determine when the battery reaches
full charge: voltage slope, battery temperature, and
charge time.
Figure 1 shows the block diagram for the MAX712/
MAX713. The timer, voltage-slope detection, and temper-
ature comparators are used to determine full charge
state. The voltage and current regulator controls output
voltage and current, and senses battery presence.
Figure 2 shows a typical charging scenario with batteries
already inserted before power is applied. At time 1, the
MAX712/MAX713 draw negligible power from the bat-
tery. When power is applied to DC IN (time 2), the
power-on reset circuit (see the POWER-_ON-_RESETsig-
nal in Figure 1) holds the MAX712/MAX713 in trickle
charge. Once POWER_ON_RESETgoes high, the device
enters the fast-charge state (time 3) as long as the cell
voltage is above the undervoltage lockout (UVLO) volt-
age (0.4V per cell). Fast charging cannot start until (bat-
tery voltage)/(number of cells) exceeds 0.4V.
When the cell voltage slope becomes negative, fast
charge is terminated and the MAX712/MAX713 revert
to trickle-charge state (time 4). When power is removed
(time 5), the device draws negligible current from the
battery.
Figure 3 shows a typical charging event using tempera-
ture full-charge detection. In the case shown, the bat-
tery pack is too cold for fast charging (for instance,
brought in from a cold outside environment). During
time 2, the MAX712/MAX713 remain in trickle-charge
state. Once a safe temperature is reached (time 3), fast
charge starts. When the battery temperature exceeds
the limit set by THI, the MAX712/MAX713 revert to trick-
le charge (time 4).
TIME
VOLTAGE
CELL VOLTAGE (V)
CURRENT INTO CELL
CELL TEMPERATURE
1. NO POWER TO CHARGER
2. CELL VOLTAGE LESS THAN 0.4V
3. FAST CHARGE
4. TRICKLE CHARGE
5. CHARGER POWER REMOVED
TEMPERATURE
Figure 2. Typical Charging Using Voltage Slope
TIME
CELL TEMPERATURE
CURRENT INTO CELL
TLO
THI3
1. NO POWER TO CHARGER
2. CELL TEMPERATURE TOO LOW
3. FAST CHARGE
4. TRICKLE CHARGE
Figure 3. Typical Charging Using Temperature
TIME
VREF = VLIMIT
CELL VOLTAGE (V)
CURRENT INTO CELL3
1. BATTERY NOT INSERTED
2. FAST CHARGE
3. TRICKLE CHARGE
4. BATTERY REMOVED
Figure 4. Typical Charging with Battery Insertion
MAX712/MAX713
NiCd/NiMH Battery
Fast-Charge ControllersThe MAX712/MAX713 can be configured so that voltage
slope and/or battery temperature detects full charge.
Figure 4 shows a charging event in which a battery is
inserted into an already powered-up MAX712/MAX713.
During time 1, the charger’s output voltage is regulated
at the number of cells times VLIMIT. Upon insertion of
the battery (time 2), the MAX712/MAX713 detect cur-
rent flow into the battery and switch to fast-charge
state. Once full charge is detected, the device reverts
to trickle charge (time 3). If the battery is removed (time
4), the MAX712/MAX713 remain in trickle charge and
the output voltage is once again regulated as in time 1.
Powering the MAX712/MAX713AC-to-DC wall-cube adapters typically consist of a trans-
former, a full-wave bridge rectifier, and a capacitor.
Figures 10–12 show the characteristics of three con-
sumer product wall cubes. All three exhibit substantial
120Hz output voltage ripple. When choosing an adapter
for use with the MAX712/MAX713, make sure the lowest
wall-cube voltage level during fast charge and full load is
at least 1.5V higher than the maximum battery voltage
while being fast charged. Typically, the voltage on the
battery pack is higher during a fast-charge cycle than
while in trickle charge or while supplying a load. The volt-
age across some battery packs may approach 1.9V/cell.
The 1.5V of overhead is needed to allow for worst-case
voltage drops across the pass transistor (Q1 of Typical
2N3904Q1DRV
DC IN
MAX712
MAX713
Figure 5. DRV Pin Cascode Connection (for high DC IN voltage
or to reduce MAX712/MAX713 power dissipation in linear mode)1x
UNDER_VOLTAGEIINN__RREEGGUULLAATTIIOONNxxxxPOOWWEERR__OONN__RREESSEETTx100xx00000↓↓00000xxxx0↑↑0
Table 4. MAX712/MAX713 Charge-State Transition Table†COOLLDDHOOTT
No change
RESULT*Set trickle
No change
No change
Set fast
No change***
No change
No change
Set fast
Set fast
Set fast**
No change***
Trickle to fast transition inhibited
Trickle to fast transition inhibited
Set trickle
Set tricklexxx↓Set trickleOnly two states exist: fast charge and trickle charge.Regardless of the status of the other logic lines, a timeout or a voltage-slope detection will set trickle charge.If the battery is cold at power-up, the first rising edge on COLD will trigger fast charge; however, a second rising edge will
have no effect.
***Batteries that are too hot when inserted (or when circuit is powered up) will not enter fast charge until they cool and power is recycled.
