SEMTECH SC805AMLTRT

POWER
POWER MANAGEMENT
MANAGEMENT
Description
Style Name _GreenBarText
Description
SC805A
Miniature Integrated High Current
Lithium-Ion Battery Charger
Features
Features
‹ Fully integrated charger with FET pass transistor,
Reverse-blocking diode, sense resistor and thermal
protection
‹ High accuracy charge current*
‹ Tiny 3mm x 3mm 10-lead MLPD package
‹ Programmable pre-charge, fast-charge and
termination current
‹ Battery voltage controlled to 1% accuracy
‹ Built-in timer for protection and complete charging
‹ NTC interface with battery detection
‹ Soft-start to reduce adapter in-rush current
‹ Up to 1A continuous charge current
‹ Input voltage range from 3V to 6V allows seamless
charging from current limited adapter
Applications
‹
Provides adapter voltage VCCIL to power external
accessories
‹ Battery present detection and output indicator
‹ Operates in charger or LDO-Mode without battery
‹ 0.1μA battery drain current in shutdown and monitor
modes
‹ Over-current protection in all charging modes
‹ CHRGB output communicates charging and
end-of-charge cycle
The SC805A is a fully integrated, single cell, constantcurrent (CC)/constant-voltage (CV) Lithium-Ion battery
charger in a tiny 3x3 mm thermally enhanced lead-free
MLP package. The SC805A can operate as a stand-alone
charger or in conjunction with a Power Management Integrated Circuit (PMIC).
The SC805A has a pre-charge function for trickle charging
deeply discharged batteries. The fast-charge current is
enabled automatically when the battery voltage reaches
the required threshold. When the battery reaches the
constant voltage or CV portion of the charge curve, the
SC805A switches to CV regulation mode. In this mode
the output current decays as the battery charges until the
termination current is reached and the SC805A signals the
charge cycle is complete. The SC805A can be configured
to continue charging for a pre-determined time before
turning off, or to turn off immediately upon termination.
After turning off its output, the SC805A enters monitor
mode. If the battery voltage drops by 100mV from the
CV voltage a new charge cycle will begin. The timer
function also protects against charging faulty batteries by
turning off if the pre-charge time exceeds ¼ of the total
programmed charge duration.
*US Patent 6,836,095
The SC805A also provides battery detection, and a battery
NTC thermistor interface to disable charging when the
battery temperature exceeds safe-to-charge limits.
Applications
‹
‹
‹
‹
‹
‹
‹
The SC805A can also function as a general purpose current
source or as a current source for charging nickel-cadmium
(NiCd) and nickel-metal-hydride (NiMH) batteries.
Typical Application Circuit
Cellular Phones
PDAs
Handheld Meters
Charging Stations
USB Chargers
Digital Cameras
Programmable Current Source
SC805A Typical Application Circuit
Charge
Complete
Indicator
SC805A
CHARGER VIN
C1
1μF
Adapter
Present
Indicator
D1
LED
R1
3.01k
R2
3.01k
RT1
Thermistor
1 VCC
VOUT
2 VCCIL
CHRGB
7 EN/NTC ITERM
8 NOBAT IPRGM
9 RTIME
GND
3
10
5
4
6
D2
LED
R4
3.01k
R5
3.01k
R3
39.2k
D3
LED
BATTERY
C1
R6
R7
1k
1k
2.2μF
Charging
Indicator
June 17, 2008
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SC805A
POWER MANAGEMENT
Absolute Maximum Rating
Exceeding the specifications below may result in permanent damage to the device or device malfunction. Operation outside of the parameters specified
in the Electrical Characteristics section is not implied.
Parameter
Symbol
Maximum
Units
VCC, VCCIL, EN/NTC to GND
-0.3 to 7.0
V
VOUT, NOBAT, IPRGM, CHRGB, ITERM, RTIME to GND
-0.3 to +6.0
V
Power Dissipation
MLP (Derate 20mW/ °C above 85°C)
PD
2
W
Thermal Impedance, Junction to Ambient
θJA
40(1)
°C/W
Junction Temperature
TJ
150
°C
Operating Ambient Temperature Range
TA
-40 to +85
°C
Peak IR Reflow Temperature, Soldering 20s-40s
TPKG
260
°C
Storage Temperature Range
TSTG
-65 to 150
°C
Continuous
A
1
A
VOUT Short to GND
IVCCIL +IVOUT Total Output Current
IOUT_TOT
Notes:
(1) Calculated from package in still air, mounted to 3” to 4.5”, 4 layer FR4 PCB with thermal vias under the exposed pad per JESD51 standards.
Electrical Characteristics
Unless otherwise noted: VCC = 4.75V - 5.25V.
TA
(-40°C to +85°C)
25°C
Parameter
Symbol
Condition
Min
Input Voltage
Typ
5
Max
Units
Min
Max
3.5
5.9
V
ICCDIS
Shutdown Mode, EN = 0
0.1
1
μA
ICCCHG
Charging Mode
CHRGB, ITERM,
IPRG = 0μA
1.2
1.55
mA
IleakBAT
VCC = 0V
0.1
1
μA
Regulated Voltage
VBAT
Vbat load = 75mA
4.20
4.16
4.24
V
Battery Pre-Charge
Current
IPREQ
50
44
54
Battery Termination
Current
ITERMQ
Operating Current
Battery Leakage
Current
© 2008 Semtech Corp.
ITERM Resistor = 3.01k
mA
50
2
44.5
53.6
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SC805A
POWER MANAGEMENT
Electrical Characteristics (Cont.)
TA
(-40°C to +85°C)
25°C
Parameter
Symbol
Condition
Min
Battery Fast-Charge
Current(1)
Typ
Max
Min
Max
Units
IFastQ1
IPRGM = 15k
100
91.5
111.5
mA
IFastQ2
IPRGM = 1.87k
787
-5
+5
%
1.0
A
VBATTERY = 3.8V
Dropout Voltage = 500mV
Battery Fast-Charge
Max Current Limit
2.8V < VBATTERY
< VBAT
IProg Regulated
Voltage
VIPRGM
1.5
1.42
1.58
V
ITerm Regulated
Voltage
VITERM
1.5
1.42
1.58
V
Vin OVP Rising
Threshold
VTOVPR
6.8
7.5
V
Vin OVP Falling
Theshold
VTOVPF
6.4
5.9
V
Vin OVP Hysteresis
VTOVPH
375
150
mV
Vin UVLO
Rising Threshold
VTUVLOR
2.8
Vin UVLO
Falling Threshold
VTUVLOF
2.75
2.5
Vin UVLO
Hysteresis
VTUVLOH
50
30
Vbat Pre-Charge
Threshold
VTPREQR
2.8
2.7
2.9
V
Vbat Recharge
Threshold
3.5
V
3.25
V
mV
VTREQ
VBAT - VBATTERY
100
60
140
mV
Pre-Charge Fault
Time-Out
TPQFAULT
Rtime = 39.2k
38
30.7
44.7
min
Charge Complete
Time-Out
TFASTQ
Rtime = 39.2k
2.5
2.0
3.0
hrs
Time Disable
Threshold
VTTIMER
Rtime VIL Voltage
1.0
0.7
V
LDO-Mode Select
Threshold
VTIINTTS
VCC-Rtime Voltage
1.1
0.7
V
© 2008 Semtech Corp.
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SC805A
POWER MANAGEMENT
Electrical Characteristics (Cont.)
TA
(-40°C to +85°C)
25°C
Parameter
Symbol
Condition
Min
Typ
Max
Min
Units
Max
VTDIS
SC805A Disable
< 1.1
VTNTCH
NTC Hot Vth Vcc = 5
0.3VCC
0.294VCC 0.314VCC
V
VTNTCC
NTC Cold Vth Vcc = 5
0.75VCC
0.736VCC 0.756VCC
V
VTNOBAT
No Battery Detect,
Vcc = 5
0.95VCC
0.93VCC
V
NTCHYS
Hot/Cold Hysteresis
50
mV
OT
Hysteresis = 10°C
150
°C
VCBVOH
Charge Complete
Isrc = 2mA
4.5
4.3
5.0
V
VCBVOL
Charging Isnk = 2mA
0.2
0.05
0.5
V
ICBOFF
Disable or LDO-mode
Off-leakage
0.1
1.0
μA
VNBVOH
EN = VCC, Isrc = 1mA
4.8
INBOFF
EN = VCC/2
Off-Leakage
0.1
VCCIL Resistance
VCCILR
R VCC to VCCIL,
1 = 100mA
0.2
Reduced
Fast-Charge Current
lfqRed
Vout = 3.8V,
Rprog = 1.87k,
VCCIL Load = 200mA
585
En-NTC Thresholds
Over-Temperature
Shutdown
CHRGB LED
Output
NOBAT Output
0.7
V
0.97VCC
4.5
V
1.0
μA
Ω
545
625
mA
Note:
(1) Charge current is reduced by VCCIL current. VCCIL current is not limited by the IC.
© 2008 Semtech Corp.
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SC805A
POWER MANAGEMENT
Pin Configuration
Ordering Information
Top View
VCC
1
10
CHRGB
VCCIL
2
9
RTIME
VOUT
3
SC805A
8
NOBAT
IPRGM
4
T
7
EN/NTC
ITERM
5
6
GND
Device
Package(1)
SC805AMLTRT(2)
MLP-10
SC805AEVB
Evaluation Board
Notes:
(1) Only available in tape and reel packaging. A reel contains 3000 devices.
(2) Lead-free product. This product is fully WEEE and RoHS compliant.
MLP-10 3mm x 3mm 10 Lead
Marking Information
805A
yyww
xxxx
Marking for the 3x3mm MLPD-10 Lead Package:
nnnn = Part Number (Example: 805A)
yyww = Datecode (Example: 0652)
xxxx = Semtech Lot No. (Example: E901)
© 2008 Semtech Corp.
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SC805A
POWER MANAGEMENT
Block Diagram
VCC
1
Reference
Voltages
GND
6
Control
Vout Ref
Fast-Charge Ref
Pre- Charge Ref
VCCIL
2
Pre-Charge On
Fast-Charge On
Over-Temp
NOBAT
Under-Voltage
8
Over-Voltage
EN/NTC
7
NTC
Interface
VOUT
Timer
RTIME
9
3
IPRGM
4
CHRGB
10
Fast-Charge Ref
ITERM
VOUT
5
Vout Ref
© 2008 Semtech Corp.
Pre-Charge Ref
6
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SC805A
POWER MANAGEMENT
Pin Descriptions (Cont.)
Pin
Pin Name
1
VCC
2
VCCIL
Adapter input voltage – this pin provides a bias voltage approximately equal to the adapter
input voltage. When charging, the output current will be reduced by the load current on
VCCIL.
3
VOUT
Charger output – connect to battery
4
IPRGM
Current limit program pin for charge and LDO-mode – requires a resistor to ground to
program fast-charge current.
5
ITERM
Selection for current termination and pre-charge current – requires a resistor to ground to
program pre-charge and termination current.
6
GND
7
EN/NTC
Combined device enable/disable and NTC input pin – logic low disables the device.
Analog voltages between 0.3VCC and 0.75VCC enable the NTC function. Voltages above
95% of VCC force the NOBAT output high.
8
NOBAT
Battery Present Indicator – this output goes high when the NTC voltage exceeds 95% of
VCC indicating the battery and NTC have been removed.
9
RTIME
Charge time programming resistor – connect a resistor between RTIME and GND to
program the charge time. Force the pin to GND to disable the timer. Force the pin to VCC
to select LDO-mode.
10
CHRGB
Output status indicator designed to drive two LEDs. Connect cathode of the ‘charging’
LED to this pin to indicate charge in progress. Connect the anode of the ‘charge’
completed to this pin to indicate charge complete.
T
Thermal Pad
© 2008 Semtech Corp.
Pin Function
Supply pin – connect to adapter power
Ground
Pad is for heatsinking purposes – not connected internally. Connect exposed pad to
ground plane with thermal vias directly under pad.
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SC805A
POWER MANAGEMENT
Applications Information
General Operation
The SC805A is configured based on the application for fastcharge and termination current, timing requirements, and
operation with and without a battery (LDO mode). A typical
charging cycle is described below. Details on alternate applications and output programmability are covered in the
individual sections.
Fast-Charge Mode (CC)
The fast-charge or CC mode is active when the battery voltage is above 2.8V and less than the CV or final float charge
voltage of the battery. The fast-charge current can be set to
a maximum of 1.0A and is selected by the program resistor
on the IPRGM pin. The voltage on this pin will represent
the current through the battery enabling a microprocessor
via an analog-to-digital converter (ADC) to monitor battery
current by sensing the voltage on the IPRGM pin. The equation to set the fast-charge current is given by:
The charging cycle begins when the adapter is plugged in.
The SC805A performs glitch filtering on the VCC input and
initiates a charge cycle when VCC > UVLO. At this time, the
CHRGB signal is active low turning on the charging LED. If
the battery voltage is less than 2.8V, the SC805A will charge
the output with the pre-charge current. When the battery
voltage exceeds 2.8V, the SC805A enters fast-charge or
constant current (CC) mode. When the battery voltage
reaches its final value, the charger enters the constant voltage (CV) mode. In this mode the output current decreases
as the battery continues to charge until the termination
current level is reached.
§ 1.5 ·
FCI ¨
¸ x 1000
© RPRGM ¹
Note that for a given program resistor the current through
the battery in CV mode can be determined by replacing
1.5 with the actual voltage on the IPRGM pin in the above
equation.
The superior fast-charge current accuracy of the SC805A is
obtained by use of US patent 6,836,095 polarity-switched
(i.e., chopped) current sense amplifier to nullify current
measurement offset errors.
The CHRGB pin goes high when VOUT output current is less
than the programmed termination current, turning off the
‘charging’ LED and turning on the ‘charge complete’ LED.
The SC805A continues to hold the battery in CV charge
mode until the timer expires. At this point the charger
enters the monitor mode where the output remains off
until VOUT drops by 100mV and a new charge cycle is
initiated.
Termination Current
Once the battery reaches the program voltage of 4.2V
the device will transition from a constant current source
to a constant voltage source and the current through the
battery begins to decrease while the voltage remains
constant. When the current falls below the programmed
termination current set by the termination resistor on the
ITERM pin, the SC805A will transition the CHRGB pin from
low to high. If the timer is enabled the output will continue
to float charge in CV mode until the timer expires. If the
timer is disabled than the output will turn off as soon as
the termination current level is reached. If the part is in
LDO mode the SC805A will remain on indefinitely at the
regulated CV voltage. The equation to set the termination
current is given by:
Pre-Charge Mode
Pre-charge mode is automatically enabled whenever the
battery voltage is below 2.8V. It is used to limit the power
dissipation and precondition the battery for fast charging.
The pre-charge current value is selected by the resistor on
the ITERM pin. The pre-charge current is programmable
from 10mA to 125mA. The equation to select the precharge current is given by:
§ 1.5 ·
PCI ¨
¸ x 100
© RTERM ¹
§ 1.5 ·
ITERM ¨
¸ x 100
© RTERM ¹
If the charge timer is in use there is also a maximum allowed pre-charge duration. If the pre-charge time exceeds
¼ of the total charge cycle, the charger will turn off due to
a pre-charge fault. This fault is cleared when EN or VCC is
toggled or the output voltage rises above 2.8V.
A sufficient separation between FCI and ITERM must be
maintained to ensure proper operation of the constant
current regulator and charge termination detector. RPRGM
and RTERM must be chosen to nominally satisfy
FCI > ITERM + 100mA
© 2008 Semtech Corp.
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SC805A
POWER MANAGEMENT
Applications Information (Cont.)
The NOBAT output can be used to signal the system that
the battery has been removed, drive an external LED, or
fed back to the SC805A to select LDO-mode.
Monitor Mode
When a charge cycle is completed, the SC805A output
turns off and the device enters monitor mode. If the
voltage of the battery falls below the recharge threshold
of CV-100mV the charger will clear the charge timer and
re-initiate a charge cycle. The maximum current drain of
the battery during monitor mode will be no more than 1μA
over temperature. The status of the charger output as a
function of RTIME, and VOUT current is shown below.
Output
State
Rtime
Timer
VOUT current
ON
VCC
N/A
N/A
ON
R
T < Timer
N/A
OFF
R
T > Timer
N/A
ON
Low
Disabled
> termination
OFF
Low
Disabled
< termination
Connect the NOBAT pin to the RTIME pin to select LDO
mode when the battery is removed and re-enable the
output of the SC805A.
LDO Mode
The SC805A is designed to work with or without a battery. If
the battery is not in place the device can enter LDO mode. In
this mode the SC805A will act like a low dropout regulator.
The input pin RTIME is used to select LDO mode. If RTIME
is high the device will be in LDO mode. When LDO mode is
selected and the EN-NTC pin is greater than 90% of VCC
the output will be on in LDO mode. During LDO mode the
device will regulate the output voltage with a current limit
set by the resistor tied to the IPRGM pin.
EN-NTC Interface
The enable pin on the SC805A provides three functions:
device disable, battery detection, and NTC temperature
protection. It can be used to turn off the device by driving
the pin to GND. It can also be connected to an external
resistor divider consisting of a resistor and an NTC Thermistor to disable the charge cycle when the temperature is out
of range. If the pin is pulled to VCC the SC805A will signal
a ‘No Battery’ condition on the NOBAT pin.
Charge Timer
The timer on the SC805A is used as protection in the case
of a faulty battery and to maximize charging capacity. Connect a resistor from the RTIME pin to GND to select the
desired charge time duration according to the following
equation.
§ RTIME ·
CHARGE TIME ¨
¸ x 2.5HRS
© 39.2k ¹
The timer is programmable over the range of 1 to 10 hours.
To disable the charge timer, connect RTIME to GND. Driving
the RTIME pin to VCC will disable the timer and select LDOmode operation for the SC805A. One implementation of
this feature is discussed in the NOBAT operating section.
Note: the SC805A will be disabled due to the NTC function
when the ‘No Battery’ condition is detected due to the NTC
feature. The NTC temperature fault can be overridden to
re-enable the output of the charger for no battery conditions
as described in the NOBAT section of the datasheet.
The SC805A will automatically turn off the output when
the charge timer times out.
The NTC external component configuration is shown in the
typical application schematic on Page 1 of the datasheet.
When the NTC voltage from the divider is above or below the
cold and hot temperature threshold values, the SC805A
will suspend the charge cycle by turning off the output,
freezing the charge timer, and indicating a fault on the
CHRGB LED. Hysteresis is included for both hot and cold
thresholds to avoid chatter at the NTC trip points. When
the temperature returns to the valid range, the SC805A will
automatically resume the charge cycle. The charge timer
will time-out when the SC805A output on-time exceeds the
timer setting regardless of how long it has been disabled
due to the NTC temperature. The internal NTC thresholds
NOBAT Output
The SC805A detects the absence of the battery by monitoring the voltage on the NTC pin. When the NTC pin voltage
exceeds 95% of VCC, the NOBAT output is driven high. This
function utilizes the standard NTC configuration with the
NTC component residing in the battery pack. When the
battery is removed the NTC element in the resistor divider
is missing and the NTC voltage is pulled up to VCC.
© 2008 Semtech Corp.
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SC805A
POWER MANAGEMENT
Applications Information (Cont.)
of 30% and 75% VCC were designed to work with Curve-2
type thermistors available from numerous vendors.
For detailed design guidance, including thermistor selection guidelines, see the Semtech Application Note
AN–PM–0801, NTC Thermistor Network Design for
Ratiometric Thresholds.
Design example based on the typical application schematic
of Page 1 using a Curve--2, Vishay-Dale NTC.
Thot = 50°C
Tcold = 0°C
Find R2 and RT1
CHRGB LED Flag
The CHRGB LED driver on the SC805A can be used to
drive two external LEDs: CHRGB=Low (charging) and
CHRGB=High (charge complete). The CHRGB output will
be high impedance when the VCC is in a UV condition. The
table below defines the CHRGB LED output states.
Step 1: Pick an RT1 value high enough to prevent selfheating.
§ V(RT 1) ·
RT 1 t ¨
¸
© DC ¹
2
In general, lower values of RT1 provide more noise immunity for the NTC voltage at the expense of bias current from
the input adapter. The dissipation constant DC is the power
rating of the NTC resulting in a 1°C self-heating error.
Step 2: Find R2 to set the correct hot level trip point,
9.52k
The closest standard resistor value is 9.53k. RT(temp)/
RT(25°C) is often referred to as the ratio at the given temp.
For this NTC at 50°C, the ratio is 0.4086.
§ R2 ·
3x¨
¸
© 10K ¹
Blinking
CHRGB
Iout <
Iterm
Iout > term
VCC < UV
Pre-charge
OV or NTC
Fault
There are five fault modes detected by the SC805A; (input
under-voltage, input over-voltage, NTC temperature, max
die temperature (or OT) and pre-charge timeout). The LED
states for these fault modes are shown in the following
table.
2.86
The ratio for the Curve-2 NTC at 0°C is 2.816. The difference represents less than 1/2°C (i.e., actual trip would be
-0.5°C instead of 0°C.) For temperature trip values other
than 0°C and 50°C, alternate curve-type NTC elements can
be used or an additional resistor can be added to the Rntc
divider to alter the temperature coefficient.
© 2008 Semtech Corp.
High-Z
The CHRGB output can be used for a VCC indicator. When
the SC805A is enabled the CHRGB output is either high or
low providing the VCC input is above UVLO. Alternately an
LED connected to VCCIL can be used for a VCC indicator as
shown in the typical application schematic on Page 1.
Step 3: Calculate the Tcold value.
§ RTCOLD ·
¨
¸
© RT25 ¹
Low
The CHRGB output signifies the charging status. When
the output current is greater than termination current,
CHRGB=low. CHRGB is high when Iout is < Itermination.
The CHRGB output is latched high at the end of the charge
cycle when the output current is less than Itermination.
The CHRGB output will remain high until the timer expires
and Vbatt enters a re-charge cycle, or if EN, or VCC are
toggled. The CHRGB indicator operates the same way in
both charge and LDO mode.
Set RT1 = 10k
§
§ RT50 · ·
2.33 x ¨¨ RT25 x ¨
¸ ¸¸
© RT25 ¹ ¹
©
High
The CHRGB output can be used for a VCC indicator. When
the SC805A is enabled, the CHRGB output is either high
or low providing the VCC input is above UVLO.
The DC value for this NTC is 3mW and the voltage across
the NTC is 2.5V for a 5V adapter. Therefore, RT1 > 2K,
R2
LED
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SC805A
POWER MANAGEMENT
Applications Information (Cont.)
Fault
CHRGB
VCC UVLO
High-Z
VCC OVP
Blinking
NTC Fault
Blinking
Pre-Charge Time-Out
Blinking
TJ > 150°C
Blinking
the battery - terminal to the adapter - input. All of these
traces need to be designed to handle the required charging
current. The trace from VOUT of the SC805A is most critical
and should be made as wide as possible to minimize I×R
drops between the regulated voltage at the SC805A VOUT
pin and the battery terminal. Keep the Adapter+ to SC805A
VCC input trace wide to minimize voltage drops that will
add to the dropout voltage of the SC805A. The GND pin
of the SC805A should be connected in a Kelvin fashion at
the battery-terminal to eliminate voltage drops in the return
path which reduce the regulated battery voltage.
Over-Current and Max Temperature Protection
Over-current protection is inherent in all modes of operation. When the device is in charge-mode the output is current-limited to either the pre-charge current limit value or
the fast-charge current limit value depending on the voltage
at the output. When the device is in LDO mode, the output
current is limited to the fast-charge current limit. Max die
temperature protection is included on the SC805A. This
feature allows the SC805A to operate with maximum power
dissipation by disabling the output current when the die
temperature reaches OT. The result is that the SC805A
will operate as a pulse charger in extreme power dissipation applications delivering the maximum allowable output
current while regulating the internal die temperature to a
safe level.
The thermal performance of the SC805A package requires
a low impedance connection from the heat slug on the
bottom of the package to an external ground plane. This
is best accomplished by using a single large via under the
device connected to a ground plane on the bottom exposed
side of the PCB. The evaluation board uses 1 square inch
of copper on the bottom of the PCB and is capable of 1A
charging current.
The input and output bulk decoupling capacitors for the
SC805A should be placed near the external terminals for
the adapter and battery. This short low impedance loop
is for the high current spikes that result from input/output
hot-plugging of the charger. To minimize these current
spikes the value of the decoupling capacitor should be minimized. A typical application requires a 0.1μF input/output
capacitor. If the distance from the external terminals to
the SC805A is greater than 1 inch, 0.1μF local decoupling
capacitors at the SC805A may be required.
Layout Guidelines
The two most critical aspects of the PCB layout are the
power path and thermal layout. The power path starts
at the Adapter + input and runs to the VCC input of the
SC805A, then from the VOUT pin of the SC805A to the battery + terminal, and completes with the return trace from
© 2008 Semtech Corp.
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SC805A
POWER MANAGEMENT
Evaluation Board Schematic
Vout+
1
R806
No Pop
R805
0
R4
1e6
CHRGB VCCIL
Charge
Complete
Indicator
C2
1uF
1
D1
D2
D3
LED
LED
No Pop
R1
R2
1k
1k
R12
3
10
2
8
7
1
EN-NTC
1
0
SC805A
VCC
VOUT
CHRGB RTIME
VCCIL ITERM
NOBAT IPRGM
EN-NTC GND
CHRG+
1
9
5
4
6
1
C1
R7 No Pop
R3
2.2uF
R8 No Pop
No Pop
Charging
Indicator
NOBAT
Adapter
Present
Indicator
IPGM
1
R6
3.01K
1
R5
1e6
VOUT-
R9
3.01K
ITRM
1
R10
3.01K
RTIME
1
R11
40K
CHRG1
1
© 2008 Semtech Corp.
12
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SC805A
POWER MANAGEMENT
Typical Characteristics
Battery Charge Profile
VOLTAGE (Volts)
4.2
0.5
4
0.4
3.8
3.6
0.3
0.2
3.4
0.1
3:45:00
Pre-Charge/Termination Current vs. Rterm
90
80
20
Rpgrm Value (Ω)
0.25
140
6
Fast-Charge Timeout
100
5
80
4
60
3
40
2
1E+05
1E+05
90000
0
70000
0
50000
20
30000
1
Drop-out Voltage (V)
120
Pre-Charge Time-out
Vdrop
Pre-Charge Time-out (min)
8
0.2
0.65
0.6
0.55
0.15
0.05
0.5
0.45
0.4
0.35
0
0.3
0.25
0.1
100
250
500
Output Current (mA)
Rtime (Ω)
© 2008 Semtech Corp.
0.75
0.7
Rout
Drop-out Resistance (Ω)
Drop-out Voltage f(Iout)
Charge Timer vs. Rtime
9
7
30000
0
15000
10
7500
30000
15000
7500
5000
3750
3000
2500
2140
100
30
5000
200
40
3750
300
50
3000
400
60
2500
500
2140
Output Current (mA)
600
Pre-Charge Current
70
1870
Fast Charge Current
700
15000
3:32:30
I CHARGE
Rpgrm Value (Ω)
Fast-Charge Time-out (hrs)
3:20:00
3:07:30
2:55:00
2:42:30
2:30:00
2:17:30
2:05:00
1:52:30
1:40:00
1:15:00
1:27:30
V CHRGB
Fast-Charge Current vs. Rprgm Value
1870
Output Current (mA)
1:02:30
V CHARGE
800
0
0
TIME
VCHRGB voltage not to scale.
Shown to indicate timing
900
0:50:00
0:37:30
0:12:30
0:00:00
3
0:25:00
3.2
CURRENT (Amps)
0.6
4.4
13
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SC805A
POWER MANAGEMENT
Typical Characteristics (Cont.)
Fast-Charge Current Line Regulation f(Vin)
4.00%
500
3.00%
499
2.00%
498
1.00%
497
0.00%
496
-1.00%
495
-2.00%
493
2.00%
499
1.00%
0.00%
498
-1.00%
497
496
0.02%
4.206
0.00%
4.205
-0.02%
4.204
-0.04%
Unloaded Vout
Loaded Vout
Unloaded Error (%)
Loaded Error (%)
-0.06%
Output Voltage (V)
4.207
0.00%
-0.01%
4.21
Percent Error (%)
-0.02%
4.209
-0.03%
4.208
-0.04%
-0.05%
4.207
4.206
Loaded Vout
-0.06%
Loaded Error (%)
-0.07%
-0.08%
4.205
-0.08%
-0.09%
4.204
-0.10%
-0.10%
500
450
400
350
300
250
200
150
100
50
0
6.5
Output Current (mA)
Pre-Charge Current Limit, Vcc < 4.2V
CC Current Limit, VCC < 4.2V
5.00%
51.0
5.00%
490.0
0.00%
49.0
0.00%
-10.00%
430.0
Fast-Charge Current
% Error
410.0
-15.00%
-20.00%
390.0
47.0
-5.00%
45.0
Percent Error (%)
-5.00%
450.0
Percent Error (%)
470.0
Output Current (mA)
510.0
-10.00%
43.0
Pre-Charge Current
% Error
41.0
-15.00%
-20.00%
39.0
Input Voltage VCC (V)
© 2008 Semtech Corp.
5.5
5
4.5
4
-30.00%
3
35.0
5.5
-30.00%
5
350.0
4.5
-25.00%
4
37.0
3.5
-25.00%
3
370.0
3.5
Output Voltage (V)
0.04%
4.211
Input Voltage VCC (V)
Output Current (mA)
4.20
4.15
4.208
0.06%
6.0
4.10
0.08%
5.5
4.00
4.209
5.0
3.80
Output Voltage Load Regulation f(Iout)
0.10%
4.5
3.60
Output Voltage Vout (V)
Output Voltage Line Regulation f(Vin, Iout)
4.201
-3.00%
-5.00%
3.40
6.5
3.20
6
4.21
4.202
-2.00%
Fast Charge Error (%)
-4.00%
3.00
5.1 5.5 5.75
Input Voltage VCC (V)
4.203
Fast Charge Current
495
-5.00%
4.5 4.7 4.9
3.00%
-4.00%
492
4.3
4.00%
500
-3.00%
Fast Charge Current
Fast Charge Error (%)
5.00%
Percent Error (%)
494
501
Percent Error (%)
5.00%
501
Output Current (mA)
502
Percent Error (%)
Output Current (mA)
Fast-Charge Current Line Regulation f(Vin)
Input Voltage Vcc (V)
14
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SC805A
POWER MANAGEMENT
State Diagram
Under-Voltage will force the
SC805A into Shutdown Mode
from any state.
OVP> Vin > UVLO
Over-Voltage will disable
the output, suspend the
timer, and blink CHRGB.
Shutdown Mode
Vout/Iout off
CHRGB High Z
En=Hi
Yes
Soft Start Vout
CC=Constant Current
CV=Constant Voltage
CHRGB Low
Timer
Enabled?
Yes
Soft Start CC Mode
Start Timer
Iout=1500/Rprog
Time=0
Start Pre -Charge
Vout=CV
Yes
Yes
Vout>2.8V
Start CV Mode
Iout =150/Rterm
Timer
Enabled?
Iout<Iterm
Yes
Time>Tmax/4
Yes
CHRGB High
Yes
Iout<Iterm
CHRGB High
Yes
Monitor Mode
Vout=off
Yes
Vout< CV-100mV
© 2008 Semtech Corp.
Yes
Time>Tmax
Yes
Pre - Charge
Timeout Fault
CHRGB blinks at 1Hz
Cleared by
Vbat >2.8V or
Re - cycle EN or VCC
0o C > NTC Temp >50o C
Time>Tmax
NTC out of Range Fault
CHRGB blinks at 1Hz
Timer is frozen
Charge resumes when NTC
Temperature is valid
Float Charge Mode
Vout = CV
15
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SC805A
POWER MANAGEMENT
Outline Drawing - MLPD-3x3-10
D
A
DIMENSIONS
INCHES
MILLIMETERS
DIM
MIN NOM MAX MIN NOM MAX
B
A
A1
A2
b
D
D1
E
E1
e
L
N
aaa
bbb
E
PIN 1
INDICATOR
(LASER MARK)
A
.031
.039
.000
.002
(.008)
.007 .009 .011
.114 .118 .122
.074 .079 .083
.114 .118 .122
.042 .048 .052
.020 BSC
.012 .016 .020
10
.003
.004
0.80
1.00
0.00
0.05
(0.20)
0.18 0.23 0.30
2.90 3.00 3.10
1.87 2.02 2.12
2.90 3.00 3.10
1.06 1.21 1.31
0.50 BSC
0.30 0.40 0.50
10
0.08
0.10
SEATING
PLANE
aaa C
C
A1
A2
D1
1
2
LxN
E/2
E1
N
e
D/2
bxN
bbb
C A B
NOTES:
1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES).
2. COPLANARITY APPLIES TO THE EXPOSED PAD AS WELL AS TERMINALS.
© 2008 Semtech Corp.
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SC805A
POWER MANAGEMENT
Land Pattern - MLPD-3x3-10
K
DIM
(C) H
G
DIMENSIONS
INCHES
MILLIMETERS
C
G
H
K
P
X
Y
Z
Z
Y
X
(.114)
.083
.055
.087
.020
.012
.031
.146
(2.90)
2.10
1.40
2.20
0.50
0.30
0.80
3.70
P
NOTES:
1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES).
2.
THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY.
CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR
COMPANY'S MANUFACTURING GUIDELINES ARE MET.
3. THERMAL VIAS IN THE LAND PATTERN OF THE EXPOSED PAD
SHALL BE CONNECTED TO A SYSTEM GROUND PLANE.
FAILURE TO DO SO MAY COMPROMISE THE THERMAL AND/OR
FUNCTIONAL PERFORMANCE OF THE DEVICE.
Contact Information
Contact Information
Semtech Corporation
Power Management Products Division
200 Flynn Road, Camarillo, CA 93012
Phone: (805) 498-2111 Fax: (805) 498-3804
www.semtech.com
© 2008 Semtech Corp.
17
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