LP3918
www.ti.com
SNVS476D – AUGUST 2007 – REVISED MAY 2013
LP3918 Battery Charge Management and Regulator Unit
Check for Samples: LP3918
FEATURES
KEY SPECIFICATIONS
•
•
1
2
•
•
•
•
•
•
•
Fully Integrated Li-Ion Battery Charger with
Thermal Regulation
USB Charge Mode
7 Low Noise LDO’s
– 2 x 300 mA
– 3 x 150 mA
– 2 x 80 mA
I2C Compatible Interface for Controlling LDO
Outputs and Charger Operation
Thermal Shutdown
Under Voltage Lockout
25-Bump Thin DSBGA Package 2.5 x 2.5 mm
Options Available on Request, Please Contact
Sales Office for Further Information;
– Level Detect on HF_PWR & PWR_ON
– LDO Charging Mode
– Custom Default Settings on Charger, and
LDO O/P's.
APPLICATIONS
•
•
•
•
•
•
•
•
50mA to 950mA Programmable Charge
Current
3.0V to 5.5V Input Voltage Range
200mV Typ. Dropout Voltage on 300 mA LDO’s
2% (Typ) Output Voltage Accuracy on LDO’s
DESCRIPTION
The LP3918 is a fully integrated charger and multiregulator unit designed for CDMA cellular phones.
The LP3918 contains a Li-Ion battery charger, 7 low
noise low dropout (LDO) voltage regulators and a
high-speed serial interface to program on/off
conditions and output voltages of individual
regulators, and also to read status information from
the PMU.
The Li-Ion charger integrates a power FET, reverse
current blocking diode, sense resistor with current
monitor output, and requires only a few external
components. Charging is thermally regulated to
obtain the most efficient charging rate for a given
ambient temperature.
LDO regulators provide high PSRR and low noise
ideally suited for supplying power to both analog and
digital loads.
CDMA Phone Handsets
Low Power Wireless Handsets
Handheld Information Appliances
Personal Media Players
Digital Cameras
Functional Block Diagram
AC Adapter
Li - Ion Charger
Ichg
Monitor
I/O
Interface
of
Baseband
Processor
Serial
Interface
Control
+
-
BB Processor
Power Domains
7 x LDO
Memory
RF
Peripheral
Devices
Figure 1. Simplified Functional Block Diagram
1
2
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2007–2013, Texas Instruments Incorporated
On products compliant to MIL-PRF-38535, all parameters are
tested unless otherwise noted. On all other products, production
processing does not necessarily include testing of all parameters.
LP3918
SNVS476D – AUGUST 2007 – REVISED MAY 2013
www.ti.com
Device Pin Diagram
Figure 2. LP3918 25 pin DSBGA Package
TOP VIEW
5
ACOK
_N
LDO7
LDO6
LDO5
VIN2
4
RESET
_N
PON
_N
TX_EN
RX_EN
LDO4
3
VSS
SCL
SDA
GNDA
LDO3
2
PS_
HOLD
PWR
_ON
HF
PWR
TCXO
_EN
LDO2
1
IMON
CHGIN
BATT
VIN1
LDO1
A
B
D
E
C
TOP VIEW
PIN DESCRIPTION
Pin #
(1)
2
Name
Type (1)
Description
A1
IMON
A
Charge current monitor output. This pin presents an analog
voltage representation of the input charging current. VIMON(mV) =
(2.47 x ICHG)(mA).
A2
PS_HOLD
DI
Input for power control from external processor/controller.
A3
VSS
G
Digital Ground pin
A4
RESET_N
DO
Reset Output. Pin stays LOW during power up sequence. 60ms
after LDO1 (CORE) is stable this pin is asserted HIGH.
A5
ACOK_N
DO
AC Adapter indicator, LOW when 4.5V – 6.0V present at CHG_IN.
B1
CHG_IN
P
DC power input to charger block from wall or car power adapters.
B2
PWR_ON
DI
Power up sequence starts when this pin is set HIGH. Internal
500kΩ pull-down resistor.
B3
SCL
DI
Serial Interface Clock input. External pull up resistor is needed, typ
1.5kΩ
B4
PON_N
DO
Active low signal is PWR_ON inverted
B5
LDO7
A
LDO7 Output (GP)
C1
BATT
P
Main battery connection. Used as a power connection for current
delivery to the battery.
C2
HF_PWR
DI
Power up sequence starts when this pin is set HIGH. Internal
500kΩ pull-down resistor.
C3
SDA
C4
TX_EN
DI
Enable control for LDO6 (TX). HIGH = Enable, LOW = Disable.
C5
LDO6
A
LDO6 Output (TX)
D1
VIN1
P
Battery Input for LDO1 - 2
D2
TCXO_EN
DI
Enable control for LDO4 (TCXO). HIGH = Enable, LOW = Disable.
D3
GNDA
G
Analog Ground pin
D4
RX_EN
DI
Enable control for LDO5 (RX). HIGH = Enable, LOW = Disable.
D5
LDO5
A
LDO5 Output (RX)
DI/O
Serial Interface, Data Input/Output Open Drain output, external pull
up resistor is needed, typ 1.5kΩ.
A: Analog. D: Digital. I: Input. DI/O: Digital Input/Output. G: Ground. O: Output. P: Power.
Submit Documentation Feedback
Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LP3918
LP3918
www.ti.com
SNVS476D – AUGUST 2007 – REVISED MAY 2013
PIN DESCRIPTION (continued)
Pin #
Type (1)
Name
Description
E1
LDO1
A
LDO1 Output (CORE)
E2
LDO2
A
LDO2 Output (DIGI)
E3
LDO3
A
LDO3 Output (ANA)
E4
LDO4
A
LDO4 Output (TCXO)
E5
VIN2
P
Battery Input for LDO3 - 7
Applications Schematic Diagram
ACOK_N PON_N
LDO7
TX_EN
LDO6
LDO5
VIN2
VBATT
LDO2
1 PF
1.5 k:
1 PF
1 PF
10 PF
1.5 k:
A5
B4
B5
C4
C5
D5
E5
RESET_N
A4
D4
RX_EN
SDA
C3
E4
LDO4
B2
D3
VBATT
1 PF
PWR_ON
GNDA
LP3918
1 PF
SCL
B3
E3
LDO3
A3
E2
LDO2
A2
E1
VSS
1 PF
PS_HOLD
A1
B1
C1
C2
D1
D2
LDO1
1 PF
VBATT
+
10 PF
10 PF
-
IMON
CHGIN
BATT
HF_PWR
VIN1
TCXO_EN
Figure 3. Applications Schematic
Device Description
The LP3918 Charge Management and Regulator Unit is designed to supply charger and voltage output
capabilities for mobile systems, e.g. CDMA handsets. The device provides a Li-Ion charging function and 7
regulated outputs. Communication with the device is via an I2C compatible serial interface that allows function
control and status read-back.
The battery charge management section provides a programmable CC/CV linear charge capability. Following a
normal charge cycle a maintenance mode keeps battery voltage between programmable levels. Power levels are
thermally regulated to obtain optimum charge levels over the ambient temperature range.
Charger Features
•
•
•
•
•
Pre-charge, CC, CV and Maintenance modes
USB Charge 100mA/450mA
Integrated FET
Integrated Reverse Current Blocking Diode
Integrated Sense Resistor
Submit Documentation Feedback
Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LP3918
3
LP3918
SNVS476D – AUGUST 2007 – REVISED MAY 2013
•
•
•
•
•
•
•
•
•
•
•
•
www.ti.com
Thermal regulation
Charge Current Monitor Output
Programmable charge current 50mA - 950mA with 50mA steps
Default CC mode current 100mA
Pre-charge current fixed 50mA
Termination voltage 4.1V, 4.2V (default), 4.3V, and 4.4V, accuracy better than +/- 0.5% (typ)
Restart level 50mV, 100mV, 150mV (default) and 200mV below Termination voltage
End of Charge 0.1C (default), 0.15C, 0.2C and 0.25C
Programmable Enable Control
Safety timer
Input voltage operating range 4.5V - 6.0V
LDO mode on LP3918TL-L option.
REGULATORS
7 Low dropout linear regulators provide programmable voltage outputs with current capabilities of 80mA, 150mA
and 300mA as given in the table below. LDO1, LDO2 and LDO3 are powered up by default with LDO1 reaching
regulation before LDO2 and LDO3 are started. LDO1, LDO3 and LDO7 can be disabled/enabled via the serial
interface. During power up LDO1 and LDO2 must reach their regulation voltage detection point for the device to
power up and remain powered. LDO4, LDO5 and LDO6 have external enable pins and may power up following
LDO2 as determined by their respective enable. Under voltage lockout oversees device start up with preset level
of 2.85V(typ).
POWER SUPPLY CONFIGURATIONS
At PMU start up, LDO1, LDO2 and LDO3 are always started with their default voltages. The start up sequence of
the LDO's is given below.
Startup Sequence
LDO1 -> LDO2 -> LDO3
LDO's with external enable control (LDO4, LDO5, LDO6) start immediately after LDO2 if enabled by logic high at
their respective control inputs.
LDO7 (and LDO1 and 3) may be programmed to enable/disable once PS_HOLD has been asserted.
Default voltages for the LDOs are shown in Table 1 and Table 2 shows the voltages that may be programmed
via the Serial Interface.
DEVICE PROGRAMMABILITY
An I2C compatible Serial Interface is used to communicate with the device to program a series of registers and
also to read status registers. These internal registers allow control over LDO outputs and their levels. The
charger functions may also be programmed to alter termination voltage, end of charge current, charger restart
voltage, full rate charge current, and also the charging mode.
This device internal logic is powered from LDO2.
Table 1. LDO Default Voltages
4
LDO
Function
mA
Default Voltage (V)
Startup Default
Enable Control
1
CORE
300
1.8
ON
SI
2
DIGI
300
3.0
ON
-
3
ANA
80
3.0
ON
SI
4
TCXO
80
3.0
OFF
TCXO_EN
5
RX
150
3.0
OFF
RX_EN
6
TX
150
3.0
OFF
TX_EN
7
GP
150
3.0
OFF
SI
Submit Documentation Feedback
Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LP3918
LP3918
www.ti.com
SNVS476D – AUGUST 2007 – REVISED MAY 2013
Table 2. LDO Output Voltages Selectable via Serial Interface
mA
1.5
1.8
1.85
2.5
2.6
2.7
2.75
2.8
2.85
2.9
2.95
3.0
3.05
3.1
3.2
3.3
1
LDO
CORE
300
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
2
DIGI
300
+
+
+
+
+
+
+
+
+
+
+
+
+
3
ANA
80
+
+
+
+
+
+
+
+
4
TCXO
80
+
+
+
+
+
+
+
+
+
+
+
5
RX
150
+
+
+
+
+
+
+
+
6
TX
150
+
+
+
+
+
+
+
+
7
GP
150
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
Absolute Maximum Ratings
(1) (2) (3)
−0.3 to +6.5V
CHG-IN,
−0.3 to +6V
VBATT =VIN1/2, BATT,HF_PWR
−0.3 to VBATT +0.3V, max 6.0V
All other Inputs
Junction Temperature (TJ-MAX)
150°C
Storage Temperature
−40°C to +150°C
Max Continuous Power Dissipation (4)
(PD-MAX) (5)
Internally Limited
ESD
(1)
(2)
(3)
(4)
(5)
(6)
(6)
Batt, VIN1, VIN2, HF_PWR, CHG_IN, PWR_ON
8kV HBM
All other pins
2kV HBM
All voltages are with respect to the potential at the GND pin.
Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions under which
operation of the device is specified. Operating Ratings do not imply performance limits. For performance limits and associated test
conditions, see the Electrical Characteristics tables.
If Military/Aerospace specified devices are required, please contact the TI Sales Office/Distributors for availability and specifications.
Care must be exercised where high power dissipation is likely. The maximum ambient temperature may have to be derated. Like the
Absolute Maximum power dissipation, the maximum power dissipation for operation depends on the ambient temperature. In
applications where high power dissipation and/or poor thermal dissipation exists, the maximum ambient temperature may have to be
derated. Maximum ambient temperature (TA_MAX) is dependent on the maximum power dissipation of the device in the application
(PD_MAX), and the junction to ambient thermal resistance of the device/package in the application (θJA), as given by the following
equation:TA_MAX = TJ_MAX-OP – (θJA X PDMAX )
Internal Thermal Shutdown circuitry protects the device from permanent damage.
The human-body model is 100pF discharged through 1.5kΩ. The machine model is a 200pF capacitor discharged directly into each pin,
MIL-STD-883 3015.7.
Operating Ratings
(1) (2)
CHG_IN
4.5 to 6.0V
VBATT =VIN1/2, BATT
3.0 to 5.5V
HF_PWR, PWR_ON
0V to 5.5V
ACOK_N, SDA, SCL, RX_EN, TX_EN, TCXO_EN, PS_HOLD, RESET_N
0V to (VLDO2 + 0.3V)
All other pins
0V to (VBATT + 0.3V)
Junction Temperature (TJ)
−40°C to +125°C
Ambient Temperature (TA)
-40 to 85°C
(1)
(2)
Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions under which
operation of the device is specified. Operating Ratings do not imply performance limits. For performance limits and associated test
conditions, see the Electrical Characteristics tables.
All voltages are with respect to the potential at the GND pin.
Submit Documentation Feedback
Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LP3918
5
LP3918
SNVS476D – AUGUST 2007 – REVISED MAY 2013
Thermal Properties
www.ti.com
(1)
Junction to Ambient Thermal Resistance θJA
Jedec Standard Thermal PCB
37°C/W
4L Cellphone Board
66°C/W
(1)
6
Junction-to-ambient thermal resistance (θJA) is taken from thermal modelling result, performed under the conditions and guidelines set
forth in the JEDEC standard JESD51-7. The value of (θJA) of this product could fall within a wide range, depending on PWB material,
layout, and environmental conditions. In applications where high maximum power dissipation exists (high VIN, high IOUT), special care
must be paid to thermal dissipation issues in board design.
Submit Documentation Feedback
Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LP3918
LP3918
www.ti.com
SNVS476D – AUGUST 2007 – REVISED MAY 2013
General Electrical Characteristics
Unless otherwise noted, VIN ( = VIN1 = VIN2 = BATT) = 3.6V, GND = 0V, CVIN1-2=10µF, CLDOX=1µF. Typical values and limits
appearing in normal type apply for TJ = 25°C. Limits appearing in boldface type apply over the entire junction temperature
range for operation, Ta = TJ = −40°C to +125°C. (1)
Symbol
IQ(STANDBY)
Parameter
Standby Supply Current
Condition
Typ
VIN= 3.6V, UVLO on, internal
logic circuit on, all other
circuits off
2
Limit
Min
Max
Units
10
µA
3.0
V
Power Monitor Functions
Battery Under-Voltage Lockout
VUVLO-R
Under Voltage Lock-out
VIN Rising
2.85
2.7
Thermal Shutdown
TSD Threshold
(2)
160
°C
LOGIC AND CONTROL INPUTS (LDO2 at 3.0V)
VIL
VIH
Input Low Level
Input High Level
IIL
Logic Input Current
RIN
Input Resistance
PS_HOLD, SDA, SCL,
RX_EN, TCXO_EN, TX_EN
0.25×VLDO2
V
PWR_ON, HF_PWR
0.25×VBATT
V
PS_HOLD, SDA, SCL,
RX_EN, TCXO_EN, TX_EN
0.75×VLDO2
V
PWR_ON, HF_PWR
0.75×VBATT
V
All logic inputs except
PWR_ON and HF_PWR
-5
+5
µA
0V ≤ VINPUT ≤ VBATT
PWR_ON, HF_PWR PullDown resistance to GND (2)
500
kΩ
LOGIC AND CONTROL OUTPUTS (LDO2 at 3.0V)
VOL
Output Low Level
VOH
Output High Level
PON_N, RESET_N, SDA,
ACOK_N
0.25×VLDO2
V
IOUT = 2mA
PON_N, RESET_N,
ACOK_N
0.75×VLDO2
V
IOUT = 2mA
(Not applicable to Open
Drain Output SDA)
(1)
(2)
All electrical characteristics having room-temperature limits are tested during production with TJ = 25°C. All hot and cold limits are
specified by correlating the electrical characteristics to process and temperature variations and applying statistical process control.
Specified by design. Not production tested.
Submit Documentation Feedback
Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LP3918
7
LP3918
SNVS476D – AUGUST 2007 – REVISED MAY 2013
www.ti.com
LDO1 (CORE) Electrical Characteristics
Unless otherwise noted, VIN ( = VIN1 = VIN2 = BATT) = 3.6V, GND = 0V, CVIN1-2=10µF, CLDOX=1µF. VOUT1 set to 3.0V output.
Note VINMIN is the greater of 3.0V or VOUT1+ 0.5V. Typical values and limits appearing in normal type apply for TJ = 25°C.
Limits appearing in boldface type apply over the entire junction temperature range for operation, Ta = TJ = −40°C to +125°C.
(1)
Symbol
VOUT1
Parameter
Output Voltage Accuracy
IOUT1
Condition
Limit
Typ
IOUT1 = 1mA, VOUT1= 3.0V
Output Voltage
Default
Output Current
VINMIN ≤ VIN ≤ 5.5V
Output Current Limit
VOUT1 = 0V
Min
Max
−2
+2
−3
+3
1.8
Units
%
V
300
mA
280
mV
600
(2)
VDO1
Dropout Voltage
IOUT1 = 300mA,
ΔVOUT1
Line Regulation
VINMIN ≤ VIN ≤ 5.5V
200
2
mV
IOUT1 = 1mA
en1
Load Regulation
1mA≤ IOUT1 ≤ 300mA
20
mV
Output Noise Voltage
10Hz≤ f≤ 100KHz,
45
µVRMS
65
dB
COUT = 1µF (3)
PSRR
tSTART-UP
TTransient
(1)
(2)
(3)
Power Supply Rejection
Ratio
F = 10kHz, COUT = 1µF
Start-Up Time from Shutdown
COUT = 1µF, IOUT1 = 300mA
Start-Up Transient
Overshoot
COUT = 1µF, IOUT1 = 300mA
IOUT1 = 20mA
(3)
60
170
µs
60
120
mV
(3)
(3)
All electrical characteristics having room-temperature limits are tested during production with TJ = 25°C. All hot and cold limits are
specified by correlating the electrical characteristics to process and temperature variations and applying statistical process control.
Dropout voltage is the input-to-output voltage difference at which the output voltage is 100mV below its nominal value. This specification
does not apply in cases it implies operation with an input voltage below the 3.0V minimum appearing under Operating Ratings. For
example, this specification does not apply for devices having 1.5V outputs because the specification would imply operation with an input
voltage at or about 1.5V.
Specified by design. Not production tested.
LDO2 (DIGI) Electrical Characteristics
Unless otherwise noted, VIN ( = VIN1 = VIN2 = BATT) = 3.6V, GND = 0V, CVIN1-2=10µF, CLDOX=1µF. Note VINMIN is the greater
of 3.0V or VOUT2+ 0.5V. Typical values and limits appearing in normal type apply for TJ = 25°C. Limits appearing in boldface
type apply over the entire junction temperature range for operation, Ta = TJ = −40°C to +125°C. (1)
Symbol
VOUT2
IOUT2
Parameter
Condition
Output Voltage Accuracy
IOUT2 = 1mA, VOUT2= 3.0V
Output Voltage
Default
Output Current
VINMIN ≤ VIN ≤ 5.5V
Typ
Limit
Min
Max
−2
+2
−3
+3
3.0
Output Current Limit
VOUT2 = 0V
VDO2
Dropout Voltage
IOUT2 = 300mA
ΔVOUT2
Line Regulation
VINMIN ≤ VIN ≤ 5.5V
Units
%
V
300
mA
280
mV
600
(2)
200
2
mV
20
mV
IOUT2 = 1mA
Load Regulation
(1)
(2)
8
1mA≤ IOUT2 ≤ 300mA
All electrical characteristics having room-temperature limits are tested during production with TJ = 25°C. All hot and cold limits are
specified by correlating the electrical characteristics to process and temperature variations and applying statistical process control.
Dropout voltage is the input-to-output voltage difference at which the output voltage is 100mV below its nominal value. This specification
does not apply in cases it implies operation with an input voltage below the 3.0V minimum appearing under Operating Ratings. For
example, this specification does not apply for devices having 1.5V outputs because the specification would imply operation with an input
voltage at or about 1.5V.
Submit Documentation Feedback
Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LP3918
LP3918
www.ti.com
SNVS476D – AUGUST 2007 – REVISED MAY 2013
LDO2 (DIGI) Electrical Characteristics (continued)
Unless otherwise noted, VIN ( = VIN1 = VIN2 = BATT) = 3.6V, GND = 0V, CVIN1-2=10µF, CLDOX=1µF. Note VINMIN is the greater
of 3.0V or VOUT2+ 0.5V. Typical values and limits appearing in normal type apply for TJ = 25°C. Limits appearing in boldface
type apply over the entire junction temperature range for operation, Ta = TJ = −40°C to +125°C.(1)
Symbol
en2
Parameter
Condition
Output Noise Voltage
10Hz≤ f≤ 100KHz,
COUT = 1µF
PSRR
tSTART-UP
tTransient
(3)
Typ
Limit
Min
Max
Units
45
µVRMS
65
dB
(3)
Power Supply Rejection
Ratio
F = 10kHz, COUT = 1µF
Start-Up Time from Shutdown
COUT = 1µF, IOUT2 = 300mA
Start-Up Transient
Overshoot
COUT = 1µF, IOUT2 = 300mA
IOUT2 = 20mA
(3)
40
60
µs
5
30
mV
(3)
(3)
Specified by design. Not production tested.
LDO3 (ANA), LDO4 (TCXO) Electrical Characteristics
Unless otherwise noted, VIN ( = VIN1 = VIN2 = BATT) = 3.6V, GND = 0V, CVIN1-2=10µF, CLDOX=1µF. TCXO_EN high. Note
VINMIN is the greater of 3.0V or VOUT3/4 + 0.5V. Typical values and limits appearing in normal type apply for TJ = 25°C. Limits
appearing in boldface type apply over the entire junction temperature range for operation, Ta = TJ = −40°C to +125°C. (1)
Symbol
VOUT3, VOUT4
Parameter
Condition
Output Voltage Accuracy
IOUT3/4 = 1mA, VOUT3/4= 3.0V
Output Voltage
LDO3 default
3.0
LDO4 default
3.0
Output Current
VINMIN ≤ VIN ≤ 5.5V
Output Current Limit
VOUT3/4 = 0V
VDO3, VDO4
Dropout Voltage
IOUT3/4 = 80mA
ΔVOUT3 , ΔVOUT4
Line Regulation
VINMIN ≤ VIN ≤ 5.5V
IOUT3, IOUT4
Typ
Limit
Min
Max
−2
+2
−3
+3
Units
%
V
80
mA
220
mV
160
(2)
180
2
mV
IOUT3/4 = 1mA
en3,en4
Load Regulation
1mA≤ IOUT3/4 ≤ 80mA
20
mV
Output Noise Voltage
10Hz ≤ f ≤ 100kHz,
45
µVRMS
65
dB
COUT = 1µF (3)
PSRR
Power Supply Rejection
Ratio
F = 10kHz, COUT = 1µF
tSTART-UP
Start-Up Time from Shutdown
COUT = 1µF, IOUT3/4 = 80mA
40
60
µs
tTransient
Start-Up Transient
Overshoot
COUT = 1µF, IOUT3/4 = 80mA
5
30
mV
(1)
(2)
(3)
IOUT3/4 = 20mA
(3)
(3)
(3)
All electrical characteristics having room-temperature limits are tested during production with TJ = 25°C. All hot and cold limits are
specified by correlating the electrical characteristics to process and temperature variations and applying statistical process control.
Dropout voltage is the input-to-output voltage difference at which the output voltage is 100mV below its nominal value. This specification
does not apply in cases it implies operation with an input voltage below the 3.0V minimum appearing under Operating Ratings. For
example, this specification does not apply for devices having 1.5V outputs because the specification would imply operation with an input
voltage at or about 1.5V.
Specified by design. Not productino tested.
LDO5 (RX), LDO6 (TX), LDO7 (GP) Electrical Characteristics
Unless otherwise noted, VIN ( = VIN1 = VIN2 = BATT) = 3.6V, GND = 0V, CVIN1-2=10µF, CLDOX=1µF. RX_EN, TX_EN high.
LDO7 Enabled via Serial Interface. Note VINMIN is the greater of 3.0V or VOUT5/6/7 + 0.5V. Typical values and limits appearing in
normal type apply for TJ = 25°C. Limits appearing in boldface type apply over the entire junction temperature range for
Submit Documentation Feedback
Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LP3918
9
LP3918
SNVS476D – AUGUST 2007 – REVISED MAY 2013
www.ti.com
LDO5 (RX), LDO6 (TX), LDO7 (GP) Electrical Characteristics (continued)
Unless otherwise noted, VIN ( = VIN1 = VIN2 = BATT) = 3.6V, GND = 0V, CVIN1-2=10µF, CLDOX=1µF. RX_EN, TX_EN high.
LDO7 Enabled via Serial Interface. Note VINMIN is the greater of 3.0V or VOUT5/6/7 + 0.5V. Typical values and limits appearing in
normal type apply for TJ = 25°C. Limits appearing in boldface type apply over the entire junction temperature range for
operation, Ta = TJ = −40°C to +125°C. (1)
operation, Ta = TJ = −40°C to +125°C.
Symbol
VOUT5, VOUT6,
VOUT7
(1)
Parameter
Output Voltage
Output Voltage
Condition
IOUT5/6/7 = 1mA, VOUT5/6/7=
3.0V
LDO5 default
3.0
LDO6 default
3.0
LDO7 default
3.0
IOUT5, IOUT6,
IOUT7
Output Current
VINMIN ≤ VIN ≤ 5.5V
Output Current Limit
VOUT5/6/7 = 0V
VDO5, VDO6,
VDO7
Dropout Voltage
IOUT5/6/7 = 150mA
ΔVOUT5,
Line Regulation
ΔVOUT6, ΔVOUT7
en5, en6, en7
Typ
Limit
Min
Max
−2
+2
−3
+3
Units
%
V
150
mA
240
mV
300
(2)
VINMIN ≤ VIN ≤ 5.5V
180
2
mV
IOUT5/6/7 = 1mA
Load Regulation
1mA≤ IOUT5/6/7 ≤ 150mA
20
mV
Output Noise Voltage
10Hz ≤ f ≤ 100kHz,
45
µVRMS
65
dB
COUT = 1µF (3)
PSRR
tSTART-UP
tTransient
(1)
(2)
(3)
10
Power Supply Rejection
Ratio
F = 10kHz, COUT = 1µF
Start-Up Time from Shutdown
COUT = 1µF, IOUT5/6/7 =
150mA
40
60
µs
Start-Up Transient
Overshoot
COUT = 1µF, IOUT5/6/7 =
150mA
5
30
mV
IOUT5/6/7 = 20mA
(3)
(3)
(3)
All electrical characteristics having room-temperature limits are tested during production with TJ = 25°C. All hot and cold limits are
specified by correlating the electrical characteristics to process and temperature variations and applying statistical process control.
Dropout voltage is the input-to-output voltage difference at which the output voltage is 100mV below its nominal value. This specification
does not apply in cases it implies operation with an input voltage below the 3.0V minimum appearing under Operating Ratings. For
example, this specification does not apply for devices having 1.5V outputs because the specification would imply operation with an input
voltage at or about 1.5V.
Specified by design. Not production tested.
Submit Documentation Feedback
Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LP3918
LP3918
www.ti.com
SNVS476D – AUGUST 2007 – REVISED MAY 2013
Charger Electrical Characteristics
Unless otherwise noted, VCHG-IN = 5V, VIN ( = VIN1 = VIN2 = BATT) = 3.6V.CCHG_IN = 10µF, CBATT = 30µF. Charger set to
default settings unless otherwise noted. Typical values and limits appearing in normal type apply for TJ = 25°C. Limits
appearing in boldface type apply over the entire junction temperature range for operation, Ta = TJ = −25°C to +85°C. (1) (2)
Symbol
VCHG-IN
VOK_CHG
VTERM
ICHG
Parameter
Condition
Typ
Limit
Min
Max
Input Voltage
Range
4.5
6.5
Operating Range
4.5
6
Units
V
CHG_IN OK trippoint
VCHG_IN - VBATT (Rising)
200
VCHG_IN - VBATT (Falling)
50
Battery Charge
Termination
voltage
Default
4.2
VTERM voltage
tolerance
TJ = 25°C
-0.35
+0.35
TJ = 0°C to 85°C
-1
+1
Fast Charge
Current Accuracy
ICHG = 450mA
-10
+10
%
50
950
mA
40
60
Programmable full- 6.0V ≥ VCHG_IN ≥ 4.5V
rate charge current
VBATT < (VCHG_IN - VOK_CHG)
range(default
VFULL_RATE < VBATT < VTERM
100mA)
mV
V
%
(3)
Default
100
Charge current
programming step
50
IPREQUAL
Pre-qualification
current
VBATT = 2V
50
ICHG_USB
CHG_IN
programmable
current in USB
mode
5.5V ≥ VCHG_IN ≥
4.5V
VFULL_RATE
IEOC
VRESTART
IMON
TREG
(1)
(2)
(3)
(4)
Low
100
VBATT < (VCHG_IN VOK_CHG)
VFULL_RATE < VBATT
< VTERM
mA
High
450
Default = 100mA
100
Full-rate
qualification
threshold
VBATT rising, transition from pre-qual to
full-rate charging
3.0
End of Charge
Current, % of fullrate current
0.1C option selected
10
Restart threshold
voltage
VBATT falling, transition from EOC to fullrate charge mode. Default options
selected - 4.05V
4.05
IMON Voltage 1
ICHG = 100mA
0.247
IMON Voltage 2
ICHG = 450mA
1.112
Regulated junction
temperature
mA
2.9
3.1
V
%
(4)
3.97
4.13
V
0.947
1.277
115
V
°C
All electrical characteristics having room-temperature limits are tested during production with TJ = 25°C. All hot and cold limits are
specified by correlating the electrical characteristics to process and temperature variations and applying statistical process control.
Junction-to-ambient thermal resistance (θJA) is taken from thermal modelling result, performed under the conditions and guidelines set
forth in the JEDEC standard JESD51-7. The value of (θJA) of this product could fall within a wide range, depending on PWB material,
layout, and environmental conditions. In applications where high maximum power dissipation exists (high VIN, high IOUT), special care
must be paid to thermal dissipation issues in board design.
Full charge current is specified for CHG_IN = 4.5 to 6.0V. At higher input voltages, increased power dissipation may cause the thermal
regulation to limit the current to a safe level, resulting in longer charging time.
Specified by design. Not production tested.
Submit Documentation Feedback
Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LP3918
11
LP3918
SNVS476D – AUGUST 2007 – REVISED MAY 2013
www.ti.com
Charger Electrical Characteristics (continued)
Unless otherwise noted, VCHG-IN = 5V, VIN ( = VIN1 = VIN2 = BATT) = 3.6V.CCHG_IN = 10µF, CBATT = 30µF. Charger set to
default settings unless otherwise noted. Typical values and limits appearing in normal type apply for TJ = 25°C. Limits
appearing in boldface type apply over the entire junction temperature range for operation, Ta = TJ = −25°C to +85°C. (1)(2)
Symbol
Parameter
Condition
Typ
Limit
Min
Max
Units
Detection and Timing (5)
TPOK
Power OK deglitch
time
VBATT < (VCC - VOK_CHG)
32
mS
TPQ_FULL
Deglitch time
Pre-qualification to full-rate charge
transition
230
mS
TCHG
Charge timer
Precharge mode
1
Hrs
Full Rate Charging Timeout
5
Constant Voltage Timeout
5
TEOC
(5)
12
Deglitch time for
end-of-charge
transition
230
mS
Specified by design. Not production tested.
Submit Documentation Feedback
Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LP3918
LP3918
www.ti.com
SNVS476D – AUGUST 2007 – REVISED MAY 2013
Serial Interface
Unless otherwise noted, VIN ( = VIN1 = VIN2 = BATT) = 3.6V, GND = 0V, CVIN1-2=10µF, CLDOX=1µF, and VLDO2 (DIG) = 3.0V.
Typical values and limits appearing in normal type apply for TJ = 25°C. Limits appearing in boldface type apply over the
entire junction temperature range for operation, Ta = TJ = −40°C to +125°C. (1) (2)
Symbol
Parameter
Condition
Typ
Limit
Min
Max
fCLK
Clock Frequency
tBF
Bus-Free Time between
START and STOP
1.3
µs
tHOLD
Hold Time Repeated START
Condition
0.6
µs
tCLK-LP
CLK Low Period
1.3
µs
tCLK-HP
CLK High Period
0.6
µs
tSU
Set-Up Time Repeated
START Condition
0.6
µs
tDATA-HOLD
Data Hold Time
50
ns
tDATA-SU
Data Set-Up Time
100
ns
tSU
Set-Up Time for STOP
Condition
0.6
µs
tTRANS
Maximum Pulse Width of
Spikes that Must be
Suppressed by the Input
Filter of both DATA & CLK
Signals
(1)
(2)
400
Units
50
kHz
ns
All electrical characteristics having room-temperature limits are tested during production with TJ = 25°C. All hot and cold limits are
speficied by correlating the electrical characteristics to process and temperature variations and applying statistical process control.
Specified by design. Not production tested.
Submit Documentation Feedback
Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LP3918
13
LP3918
SNVS476D – AUGUST 2007 – REVISED MAY 2013
www.ti.com
REGISTER INFORMATION, SLAVE ADDRESS CODE 7H’7E
Table 3. Control Registers (1) (2)
(1)
(2)
Addr
Register
(default
value)
8h'00
D7
D6
D5
D4
D3
D2
D1
D0
OP_EN
(0000 0101)
X
X
X
X
LDO7_EN
LDO3_EN
X
LDO1_EN
8h'01
LDO1PGM
O/P
(0000 0001)
X
X
X
X
V1_OP[3]
V1_OP[2]
V1_OP[1]
V1_OP[0]
8h'02
LDO2PGM
O/P
(0000 1011)
X
X
X
X
V2_OP[3]
V2_OP[2]
V2_OP[1]
V2_OP[0]
8h'03
LDO3PGM
O/P
(0000 1011)
X
X
X
X
V3_OP[3]
V3_OP[2]
V3_OP[1]
V3_OP[0]
8h'04
LDO4PGM
O/P
(0000 1011)
X
X
X
X
V4_OP[3]
V4_OP[2]
V4_OP[1]
V4_OP[0]
8h'05
LDO5PGM
O/P
(0000 1011)
X
X
X
X
V5_OP[3]
V5_OP[2]
V5_OP[1]
V5_OP[0]
8h'06
LDO6PGM
O/P
(0000 1011)
X
X
X
X
V6_OP[3]
V6_OP[2]
V6_OP[1]
V6_OP[0]
8h'07
LDO7PGM
O/P
(0000 1011)
X
X
X
X
V7_OP[3]
V7_OP[2]
V7_OP[1]
V7_OP[0]
8h'0C
STATUS
(0000 0000)
PWR_ON
_TRIG
HF_PWR
_TRIG
CHG_IN
_TRIG
X
X
X
X
X
8h'10
CHGCNTL1
(0000 1001)
USBMODE
_EN
CHGMODE
_EN
Force EOC
TOUT_
doubling
EN_Tout
En_EOC
X
EN_CHG
8h'11
CHGCNTL2
(0000 0001)
Prog_
ICHG[4]
Prog_
ICHG[3]
Prog_
ICHG[2]
Prog_
ICHG[1]
Prog_
ICHG[0]
8h'12
CHGCNTL3
(0001 0010)
VTERM[1]
VTERM[0]
Prog_
EOC[1]
Prog_
EOC[0]
Prog_
VRSTRT[1]
Prog_
VRSTRT[0]
8h'13
CHGSTATU
S1
EOC
Tout_
Fullrate
Tout_
Prechg
LDO Mode
Fullrate
PRECHG
8h'14
CHGSTATU
S2
Tout_
ConstV
Bad_Batt
8h'1C
MISC
Control1
APU_TSD_
EN
PS_HOLD
_DELAY
Batt_Over
_Out
CHGIN_
OK_Out
X = Not Used
(R/O) = Bits are Read Only type.
Codes other than those shown in the table are disallowed.
Note that for Serial Interface operation and thus register control, LDO2 must be active to provide the power for the internal logic.
LDO Output Voltage Programming
The following table summarizes the supported output voltages for the LP3918. Default voltages after startup are
highlighted in bold.
Data Code
(Reg 01 - 07)
LDO1
V
8h'00
1.5
1.5
8h'01
1.8
1.8
1.8
8h'02
1.85
1.85
1.85
8h'03
2.5
2.5
2.5
2.5
8h'04
2.6
2.6
2.6
2.6
14
LDO2
V
VLDO3
V
LDO4
V
Submit Documentation Feedback
LDO5
V
LDO6
V
LDO7
V
1.5
Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LP3918
LP3918
www.ti.com
SNVS476D – AUGUST 2007 – REVISED MAY 2013
8h'05
2.7
2.7
2.7
2.7
2.7
2.7
2.7
8h'06
2.75
2.75
2.75
2.75
2.75
2.75
2.75
8h'07
2.8
2.8
2.8
2.8
2.8
2.8
2.8
8h'08
2.85
2.85
2.85
2.85
2.85
2.85
2.85
8h'09
2.9
2.9
2.9
2.9
2.9
2.9
2.9
8h'0A
2.95
2.95
2.95
2.95
2.95
2.95
2.95
8h'0B
3.0
3.0
3.0
3.0
3.0
3.0
3.0
8h'0C
3.05
3.05
3.05
3.05
3.05
3.05
3.05
8h'0D
3.1
3.1
3.1
3.1
8h'0E
3.2
3.2
3.2
3.2
8h'0F
3.3
3.3
3.3
3.3
Charger Control Register 2
Note that Bits 7,6,5 are not used and must be set to 0 during write to this register.
CHARGER CURRENT PROGRAMMING
The following table summarizes the supported charging current values for the LP3918.
Default charge current after startup is highlighted in bold
Table 4. LP3918 Charger Current Programming
Address
Register ID
8h'11
CHGCNTL2
Address
Register ID
8h'11
CHGCNTL2
Address
Register ID
8h'11
CHGCNTL2
Current Selection Prog_ICHG Bit 0 to Bit 4
00000
00001
00010
00011
00100
00101
00110
50mA
100mA
150mA
200mA
250mA
300mA
350mA
00111
01000
400mA
450mA
Current Selection Prog_ICHG Bit 0 to Bit 4
01001
01010
01011
01100
01101
500mA
550mA
600mA
650mA
700mA
Current Selection Prog_ICHG Bit 0 to Bit 4
01110
01111
10000
10001
10010
750mA
800mA
850mA
900mA
950mA
Charger Control Register 3
CHARGER TERMINATION VOLTAGE PROGRAMMING
Table 5. LP3918 Charger Termination Voltage Control
Address
8h'12
Register ID
CHGCNTL3
VTERM Selection Bits
VTERM[1]
VTERM[0]
Termination Voltage(V)
CHGCNTL3
CHGCNTL3
0
0
4.1
0
1
4.2 (Default)
1
0
4.3
1
1
4.4
Submit Documentation Feedback
Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LP3918
15
LP3918
SNVS476D – AUGUST 2007 – REVISED MAY 2013
www.ti.com
END OF CHARGE CURRENT PROGRAMMING
Table 6. LP3918 EOC Current Control
Address
8h'12
Register ID
End Of Charge Current Selection Bits
PROG_EOC[1]
PROG_EOC[0]
CHGCNTL3
CHGCNTL3
0
0
0.1 (Default)
0
1
0.15C
1
0
0.2C
1
1
0.25C
CHGCNTL3
End Of Charge Current
CHARGING RESTART VOLTAGE PROGRAMMING
Table 7. LP3918 Charging Restart Voltage
Address
8h'12
Register ID
Charging Restart Voltage Selection Bits
PROG_VRSTRT[1]
PROG_VRSTRT[1]
CHGCNTL3
CHGCNTL3
0
0
VTERM - 50mV
0
1
VTERM - 100mV
1
0
VTERM - 150mV
1
1
VTERM - 200mV
CHGCNTL3
Restart Voltage(V)
Charger Control Register 1
CHARGING MODE SELECTION
Charging mode selection changes will only take place when the battery voltage is above the 3.0V precharge/Full-rate charge threshold.
Table 8. LP3918 USB Charging Selection
Address
8h'10
16
Register ID
CHGCNTL1
USB Charge Mode Control Bits
USB_Mode_En
CHG_Mode_En
CHGCNTL1
CHGCNTL1
Mode
Current
0
0
Fast Charge
Default or
Selection
1
0
Fast Charge
Default or
Selection
0
1
USB
100mA
1
1
USB
450mA
Submit Documentation Feedback
Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LP3918
LP3918
www.ti.com
SNVS476D – AUGUST 2007 – REVISED MAY 2013
Device Power Up and Shutdown Timing
Figure 4. Device Power Up Logic Timing. PWR_ON
PWR_ON
30 ms Debounce time
PWR_HOLD needs to be asserted while
PWR_ON is high.
PS_HOLD
LDO1
87% Reg
< 200 Ps
LDO2
87% Reg
60 ms
RESET
I2C Control
LDO3
LDO7
RX_EN, TX_EN,
TCXO_EN
LDO4,5,6
Note: Serial I/F commands only take place
after PS_HOLD is asserted.
Submit Documentation Feedback
Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LP3918
17
LP3918
SNVS476D – AUGUST 2007 – REVISED MAY 2013
www.ti.com
Figure 5. Device Power Up Logic Timing. CHG_IN, HF_PWR
If charger is connected (CHG_IN) or HF_PWR is
applied, then both events are filtered for 320 ms
before enabling LDO1
320 ms
CHG_IN
PS_HOLD needs to be asserted within 1200 ms after
CHG_IN or HF_PWR rising edge has been detected.
(HF_PWR level detected for LP3918TL-C)
HF_PWR
1.2s
Debounce time before normal start up sequence, 320 ms.
PS_HOLD high < 1.2s from I/P detection
PS_HOLD
LDO1
87% Reg
< 200 Ps
LDO2
87% Reg
60 ms
RESET
I2C Control
LDO3
LDO7
RX_EN, TX_EN,
TCXO_EN
LDO4,5,6
Note: Serial I/F commands only take place
after PS_HOLD is asserted.
18
Submit Documentation Feedback
Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LP3918
LP3918
www.ti.com
SNVS476D – AUGUST 2007 – REVISED MAY 2013
Figure 6. LP3918 Power On Behaviour (Failed PS_Hold)
If charger is connected (CHG_IN) or HF_PWR is
applied, then both events are filtered for 320 ms
320 ms before enabling LDO1
CHG_IN
PS_HOLD needs to be asserted within 1200 ms
after HF_PWR, or CHG_IN rising edge has been
detected.
1.2s
HF_PWR
Either HF_PWR or CHG_IN will enable LDO1
If no enabling signal is high on
the rising edge of PS_HOLD,
shutdown will occur.
PS_HOLD
87%
LDO1
200 Ps
87% Reg
LDO2
60 ms
RESET
Figure 7. LP3918 Normal Shutdown Behaviour
35 ms
PS_HOLD
RESET
If PS_HOLD is low 35 ms after initially going low,
then LDO2-7 are shutdown
LDO2 - 7
LDO1 is shutdown 40 Ps after other
LDO's are shutdown
LDO1
40 Ps
Submit Documentation Feedback
Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LP3918
19
LP3918
SNVS476D – AUGUST 2007 – REVISED MAY 2013
www.ti.com
Functional Block Diagram
VBATT
10 PF
BATT
CHG_IN
Battery
10 PF
VIN1
+
10 PF
VIN2
AC Adapter or
VBUS supply
4.5V to 6V
LDO1
IMON
LDO2
LDO1
Linear Charger
1 PF
CORE
1.8V
@300 mA
ACOK_N
LDO2
LDO2
1 PF
Thermal
Shutdown
LDO3
LDO3
1 PF
UVLO
Voltage
Reference
ANA
3.0V
@80 mA
TCXO_EN
LDO4
LDO2
320 ms
debounce
1.5k
DIGI
3.0V
@300 mA
LDO4
1 PF
TCXO
3.0V
@80 mA
1.5k
RX_EN
SDA
O/D output
LDO5
LDO2
LDO5
1 PF
SCL
PON_N
RX
3.0V
@150 mA
TX_EN
PS_HOLD
LDO6
LDO6
RESET_N
HF_PWR
320 ms
debounce
PWR_ON
30 ms
debounce
Serial
Interface
and Control
LDO7
500k
500k
VBATT
1 PF
LDO7
1 PF
TX
3.0V
@150 mA
GP
3.0V
@150 mA
VSS
GNDA
LP3918
Figure 8. LP3918 Functional Block Diagram
20
Submit Documentation Feedback
Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LP3918
LP3918
www.ti.com
SNVS476D – AUGUST 2007 – REVISED MAY 2013
TECHNICAL DESCRIPTION
BATTERY CHARGE MANAGEMENT
A charge management system allowing the safe charge and maintenance of a Li-Ion battery is implemented on
the LP3918. This has a CC/CV linear charge capability with programmable battery regulation voltage and end of
charge current threshold. The charge current in the constant current mode is programmable and a maintenance
mode monitors for battery voltage drop to restart charging at a preset level. A USB charging mode is also
available with 2 charge current levels.
CHARGER FUNCTION
Following the correct detection of an input voltage at the charger pin the charger enters a pre-charge mode. In
this mode a constant current of 50mA is available to charge the battery to 3.0V. At this voltage level the charge
management applies the default (100mA) full rate constant current to raise the battery voltage to the termination
voltage level (default 4.2V). The full rate charge current may be programmed to a different level at this stage.
When termination voltage (VTERM) is reached, the charger is in constant voltage mode and a constant voltage of
4.2V is maintained. This mode is complete when the end of charge current (default 0.1C) is detected and the
charge management enters the maintenance mode. In maintenance mode the battery voltage is monitored for
the restart level (4.05V at the default settings) and the charge cycle is re-initiated to re-establish the termination
voltage level.
For start up the EOC function is disabled. This function should be enabled once start up is complete and a
battery has been detected. EOC is enabled via register CHGCNTL1, Table 9.
The full rate constant current rate of charge may be programmed to 19 levels from 50mA to 950mA. These
values are given in Table 4, and Table 11
The charge mode may be programmed to USB mode when the charger input is applied and the battery voltage is
above 3.0V. This provides two programmable current levels of 100mA and 450mA for a USB sourced supply
input at CHG_IN. Table 8
LDO Mode on device option LP3918TL-L
The charger circuit automatically enters an LDO mode if no battery is detected on insertion of the charger input
voltage. In LDO mode the battery pin is regulated to 4.2V and can source up to 1.0A of current. Normal operation
with a battery connected can be re-established via the serial interface. The serial interface allows the device to
switch between modes as required however care is required to ensure that LDO mode is not initiated while a
battery is present.
Constant Voltage
Battery Voltage
VTERM
Current
Limiting
I(Batt)
1.0A
Figure 9. LDO Mode Diagram
EOC
EOC is disabled by default and should be enabled when the system processor is awake and the system detects
that a battery is present.
Submit Documentation Feedback
Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LP3918
21
LP3918
SNVS476D – AUGUST 2007 – REVISED MAY 2013
www.ti.com
Programming Information
Table 9. Register Address 8h'10: CHGCNTL1
BIT
NAME
2
En_EOC
FUNCTION
Enables the End Of Charge current level threshold detection.
When set to '0' the EOC is disabled.
The End Of Charge current threshold default setting is at 0.1C. This EOC value is set relative to C the set full
rate constant current. This threshold can be set to 0.1C, 0.15C, 0.2C or 0.25C bychanging the contents of the
PROG_EOC[1:0] register bits.
Table 10. Register Address 8h'12: CHGCNTL3
BIT
NAME
2
Prog_EOC[0]
3
Prog_EOC[1]
FUNCTION
Set the End Of Charge Current.
See Table 8
CHARGER FULL RATE CURRENT
Programming Information
Table 11. Register Address 8h'11: CHGCNTL2
Data BITs
HEX
NAME
000[00000]
00
Prog_ICHG
FUNCTION
000[00001]
01
100mA
000[00010]
02
150mA
000[00011]
03
200mA
000[00100]
04
250mA
000[00101]
05
300mA
000[00110]
06
350mA
000[00111]
07
400mA
000[01000]
08
450mA
000[01001]
09
500mA
000[01010]
0A
550mA
000[01011]
0B
600mA
000[01100]
0C
650mA
000[01101]
0D
700mA
000[01110]
0E
750mA
000[01111]
0F
800mA
000[10000]
10
850mA
000[10001]
11
900mA
000[10010]
12
950mA
50mA
TERMINATION AND RESTART
The termination and restart voltage levels are determined by the data in the VTERM[1:0] and PROG_VSTRT[1:0]
bits in the control register. The restart voltage is programmed relative to the selected termination voltage.
The Termination voltages available are 4.1V, 4.2V (default), 4.3V, and 4.4V.
The Restart voltages are determined relative to the termination voltage level and may be set to 50mV, 100mV,
150mV (default), and 200mV below the set termination voltage level.
22
Submit Documentation Feedback
Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LP3918
LP3918
www.ti.com
SNVS476D – AUGUST 2007 – REVISED MAY 2013
Programming Information
Table 12. Register Address 8h'12: CHGCNTL3
BIT
NAME
4
VTERM[0]
5
VTERM[1]
FUNCTION
Set the charging termination voltage.
See Table 5
Table 13. Register Address 8h'12: CHGCNTL3
BIT
NAME
0
VRSTRT[0]
1
VRSTRT[1]
FUNCTION
Set the charging restart voltage.
See Table 7
Charger Operation
The operation of the charger with EOC enabled is shown in this simplified flow diagram.
From any mode:
VCHG_IN < 4.5V
or VCHG_IN > 6.0V
or disabled via serial interface.
Charger OFF
Zero Current
4.5V < VCHG_IN < 6.0V
Yes
Pre-Charge mode
50mA Constant current
VBATT > 3.0V
No
Yes
Full-Rate Charge mode
Constant Current (ICHG)
VBATT = VTERM
No
Yes
Full-Rate Charge mode
Constant Voltage (VTERM)
ICHG < EOC
No
Yes
Maintenance mode
Zero current
VBATT < VRSTRT
No
Yes
Figure 10. Simplified Charger Functional Flow Diagram (EOC is enabled)
The charger operation may be depicted by the following graphical representation of the voltage and current
profiles.
Submit Documentation Feedback
Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LP3918
23
LP3918
SNVS476D – AUGUST 2007 – REVISED MAY 2013
www.ti.com
Prequalification to Fast
Charge transition
1.0 C
Transition to Constant
Voltage-mode
Maintenance charging
starts
VTERM
Battery Voltage /
Charging Current
VRSTRT
3.0V
Charging current
Charging current
EOC
50 mA
Time
Figure 11. Charge Cycle Diagram
Further Charger Register Information
Charger Control Register 1
Table 14. Register Address 8h'10: CHGCNTL1
BIT
NAME
7
USB_MODE
_EN
FUNCTION (if bit = '1')
Sets the Current Level in USB mode.
6
CHG_MODE
_EN
Forces the charger into USB mode when active high.
If low, charger is in normal charge mode.
5
FORCE
_EOC
Forces an EOC event.
4
TOUT_
Doubling
Doubles the timeout delays for all timeout signals.
3
EN_Tout
Enables the timeout counters. When set to '0' the timeout counters
are disabled.
2
EN_EOC
Enables the End of Charge current level threshold detection.
When set to '0' the functions are disabled.
1
Set_
LDOmode
Forces the charger into LDO mode. Function available on
LP3918TL_L.
0
EN_CHG
Charger enable.
Charger Status Register 1 Read only
Table 15. Register Address 8h'13: CHGSTATUS1
24
BIT
NAME
FUNCTION (if bit = '1')
7
BAT_OVER
_OUT
6
CHGIN_
OK_Out
5
EOC
4
Tout_
Fullrate
3
Tout_
Precharge
Set after timeout for precharge mode.
2
LDO_Mode
Only available on LP3918TL_L.
Is set when battery voltage exceeds 4.7V.
Is set when a valid input voltage is detected at CHG_IN pin.
Is set when the charging current decreases below the
programmed End Of Charge levlel.
Set after timeout on full rate charge.
Submit Documentation Feedback
Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LP3918
LP3918
www.ti.com
SNVS476D – AUGUST 2007 – REVISED MAY 2013
Table 15. Register Address 8h'13: CHGSTATUS1 (continued)
BIT
NAME
FUNCTION (if bit = '1')
1
Fullrate
Set when the charger is in CC/CV mode.
0
PRECHG
Set during precharge.
Charger Status Register 2 Read only
Table 16. Register Address 8h'13: CHGSTATUS2
BIT
NAME
FUNCTION (if bit = '1')
1
Tout_
ConstV
Set after timeout in CV phase.
0
BAD_
BATT
Set at bad battery state.
IMON CHARGE CURRENT MONITOR
Charge current is monitored within the charger section and a proportional voltage representation of the charge
current is presented at the IMON output pin. The output voltage relationship to the actual charge current is
represented in the following graph and by the equation:
VIMON(mV) = (2.47 x ICHG)(mA)
IMON VOLTAGE (V)
1.729
1.235
0.247
100
500
700
CHARGE CURRENT (mA)
Figure 12. IMON Voltage vs Charge Current
Note that this function is not available if there is no input at CHG_IN or if the charger is off due to the input at
CHG_IN being outwith the operating voltage range.
LDO Information
OPERATIONAL INFORMATION
The LP3918 has 7 LDO's of which 3 are enabled by default, LDO's 1,2 and 3 are powered up during the power
up sequence. LDO4, 5 and 6 are separately, externally enabled and will follow LDO2 in start up if their respective
enable pin is pulled high. LDO2, LDO3 and LDO7 can be enabled/disabled via the serial interface.
LDO2 must remain in regulation otherwise the device will power down. While LDO1 is enabled this must also be
in regulation for the device to remain powered. If LDO1 is disabled via I2C interface the device will not shut
down.
Submit Documentation Feedback
Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LP3918
25
LP3918
SNVS476D – AUGUST 2007 – REVISED MAY 2013
www.ti.com
INPUT VOLTAGES
There are two input voltage pins used to power the 7LDO's on the LP3918. VIN2is the supply for LDO3, LDO4,
LDO5, LDO6 and LDO7. VIN1is the supply for LDO1 and LDO2. These input voltages should be tied to the Batt
pin in the application.
PROGRAMMING INFORMATION
Enable via Serial Interface
Table 17. Register Address 8h'00: OP_EN
BIT
NAME
0
LDO1_EN
2
LDO3_EN
3
LDO7_EN
FUNCTION
Bit set to '0' - LDO disabled
Bit set to '1' - LDO enabled
Note that the default setting for this Register is [0000 0101]. This shows that LDO1 and 3 are enabled by default
whereas LDO7 is not enabled by default on start up.
LDO OUTPUT PROGRAMMING
Table 18.
Register
Add (hex)
NAME
Data Range (hex) (1)
01
LDO1PGM
O/P
03 - 0F
1.5V to 3.3V
(def. 1.8V)
02
LDO2PGM
O/P
00 - 0F
2.5V to 3.3V
(def 3.0V)
03
LDO3PGM
O/P
05 - 0C
2.7V to 3.05V
(def 3.0V)
04
LDO4PGM
O/P
00 - 0F
1.5V to 3.3V
(def 3.0V)
05
LDO5PGM
O/P
05 - 0C
2.7V to 3.05V
(def 3.0V)
06
LDO6PGM
O/P
05 - 0C
2.7V to 3.05V
(def 3.0V)
07
LDO7PGM
O/P
00 - 0F
1.5V to 3.3V
(def 3.0V)
(1)
Output Voltage
See Table 2 for full programmable range of values.
EXTERNAL CAPACITORS
The Low Drop Out Linear Voltage regulators on the LP3918 require external capacitors to ensure stable outputs.
The LDO's on the LP3918 are specifically designed to use small surface mount ceramic capacitors which require
minimum board space. These capacitors must be correctly selected for good performance
INPUT CAPACITOR
Input capacitors are required for correct operation. It is recommended that a 10µF capacitor be connected
between each of the voltage input pins and ground (this capacitance value may be increased without limit). This
capacitor must be located a distance of not more than 1cm from the input pin and returned to a clean analogue
ground. A ceramic capacitor is recommended although a good quality tantalum or film capacitor may be used at
the input.
Important: Tantalum capacitors can suffer catastrophic failures due to surge current when connected to a lowimpedance source of power (like a battery or a very large capacitor). If a tantalum capacitor is used at the input,
it must be specified by the manufacturer to have surge current rating sufficent for the application. There are no
requirements for the ESR (Equivalent Series Resistance) on the input capacitor, but tolerance and temperature
coefficient must be considered when selecting the capacitor to ensure the capacitance will remain within its
operational range over the entire operating temperature range and conditions.
26
Submit Documentation Feedback
Copyright © 2007–2013, Texas Instruments Incorporated
Product Folder Links: LP3918
LP3918
www.ti.com
SNVS476D – AUGUST 2007 – REVISED MAY 2013
Output Capacitor
Correct selection of the output capacitor is critical to ensure stable operation in the intended application.The
output capacitor must meet all the requirements specified in the recommended capacitor table over all conditions
in the application. These conditions include DC-bias, frequency and temperature. Unstable operation will result if
the capacitance drops below the minimum specified value. The LP3918 is designed specifically to work with very
small ceramic output capacitors. The LDO's on the LP3918 are specifically designed to be used with X7R and
X5R type capacitors. With these capacitors selection of the capacitor for the application is dependant on the
range of operating conditions and temperature range for that application. (See section on Capacitor
Characteristics). It is also recommended that the output capacitor be placed within 1cm from the output pin and
returned to a clean ground line.
Capacitor Characteristics
CAP VALUE (% of NOM. 1 PF)
The LDO's on the LP3918 are designed to work with ceramic capacitors on the input and output to take
advantage of the benifits they offer. For capacitance values around 1µF, ceramic capacitors give the circuit
designer the best design options in terms of low cost and minimal area. For both input and output capacitors
careful interpretation of the capacitor specification is required to ensure correct device operation. The capacitor
value can change greatly dependant on the conditions of operation and capacitor type. In particular to ensure
stability, the output capacitor selection should take account of all the capacitor parameters to ensure that the
specification is met within the application. Capacitance value can vary with DC bias conditions as well as
temperature and frequency of operation. Capacitor values will also show some decrease over time due to aging.
The capacitor parameters are also dependant on the particular case size with smaller sizes giving poorer
performance figures in general.
0603, 10V, X5R
100%
80%
60%
0402, 6.3V, X5R
40%
20%
0
1.0
2.0
3.0
4.0
5.0
DC BIAS (V)
Figure 13. Graph Showing A Typical Variation in Capacitance vs DC Bias
As an example Figure 13 shows a typical graph showing a comparison of capacitor case sizes in a Capacitance
vs DC Bias plot. As shown in the graph, as a result of DC Bias condition the capacitance value may drop below
minimum capacitance value given in the recommended capacitor table (0.7µF in this case). Note that the graph
shows the capacitance out of spec for 0402 case size capacitor at higher bias voltages. It is therefore
recommended that the capacitor manufacturers specifications for the nominal value capacitor are consulted for
all conditions as some capacitor sizes (e.g 0402) may not be suitable in the actual application. Ceramic
capacitors have the lowest ESR values, thus making them best for eliminating high frequency noise. The ESR of
a typical 1µF ceramic capacitor is in the range of 20mΩ to 40mΩ, and also meets the ESR requirements for
stability. The temperature performance of ceramic capacitors varies by type. Capacitor type X7R is specified with
a tolerance of ±15% over temperature range -55ºC to +125ºC. The X5R has similar tolerance over the reduced
temperature range -55ºC to +85ºC. Most large value ceramic capacitors (
