www.ti.com
PRODUCT PREVIEW
FEATURES
APPLICATIONS
DESCRIPTION
+
Protector
D1
8 V
R2
100 k
Additional ESD Protection
Optional Battery Monitor/Gas Gauge
Pack +
Pack -
HDQ
Vcc
Vss
HDQ
SRN
SRP
GPIO
BAT
R3
bq26150
5 k
W
R5
100
W
R4
100
W
R1
0.02
W
0.01
m
F
bq26150
SLUS641 JANUARY 2005
BATTERY PACK SECURITY AND AUTHENTICATION IC
FOR PORTABLE APPLICATIONS (bqSECURETM)
Small Thin SOT-23 Package
Provides Authentication of Battery Packs
Through a Programmable CRC With a 64-Bit
Cellular Phones
Unique Device ID
PDA and Smart Phones
16 Bytes of User-Programmable Non-Volatile
MP3 Players
Memory
Digital Cameras
Internal Time-Base Eliminates External
Internet Appliances
Crystal Oscillator
Handheld Devices
Two Automatic Low-Power Operating Modes:
Active: <20 A
Single-Wire HDQ Interface
Powered Directly From the Communication
Bus
Pass-Through HDQ Version Supports Existing
Packs With Gas Gauges
The bq26150 provides a method to authenticate battery packs, ensuring that only packs manufactured by
authorized sub-contractors are used in the end application. The bq26150 uses a 64-bit unique device ID and a
16-bit device-specific CRC to provide security. The device ID and CRC polynomial coefficients are stored
securely in each bq26150 device, allowing the host to authenticate each pack.
The bq26150 communicates to the system over a simple one-wire bidirectional serial interface. The 5kbits/s HDQ
bus interfaces reduces communications overhead in the external microcontroller. The bq26150 also uses the
HDQ bus to charge an external capacitor that provides power to the bq26150.
TYPICAL APPLICATION
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.
bqSECURE is a trademark of Texas Instruments.
PRODUCT PREVIEW information concerns products in the forma-
Copyright 2005, Texas Instruments Incorporated
tive or design phase of development. Characteristic data and other
specifications are design goals. Texas Instruments reserves the
right to change or discontinue these products without notice.
www.ti.com
PRODUCT PREVIEW
PIN ASSIGNMENT
3
2
4
5
1
V
SS
V
SS
PWR
HDQP
HDQ
Private Non-Volatile
Memory
Public Non-Volatile
Memory
64 bits
Encrypted KD
8 bits
Control
32 bits
Message
64 bits
Plaintext KD
HDQ
Communication
Power Control
Public RAM
64 bits
General Use
16 bits
Plaintext P
16 bits
Encrypted P
16 bits
Auth Code
Authentication
CRC
bq26150
SLUS641 JANUARY 2005
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.
TERMINAL FUNCTIONS
TERMINAL
I/O
DESCRIPTION
NAME
NO.
PWR
1
I/O
Power capacitor
VSS
2, 3
I
Ground
HDQP
4
I/O
Single-wire HDQ interface to 2nd HDQ device
HDQ
5
I/O
Single-wire HDQ interface to host
FUNCTIONAL BLOCK DIAGRAM
2
www.ti.com
PRODUCT PREVIEW
APPLICATION INFORMATION
+
Protector
D1
8 V
R2
100 k
Additional ESD Protection
Optional Battery Monitor/Gas Gauge
Pack +
Pack -
HDQ
Vcc
Vss
HDQ
SRN
SRP
GPIO
BAT
R3
bq26150
5 k
W
R5
100
W
R4
100
W
R1
0.02
W
0.01
m
F
FUNCTIONAL DESCRIPTION
bq26150
SLUS641 JANUARY 2005
Figure 1. Typical Application Circuit
The bq26150 provides a simple and cost effective method to authenticate battery packs for end equipment.
Security is achieved through the use of a 16-bit CRC, a 64-bit device ID, and a 32-bit random challenge. Both
the CRC polynomial and 64-bit key are unique from device to device, and are stored as encrypted text in public
memory, and as plain text in private memory. The host system can decrypt the polynomial and key values using
a shared key that is stored in end-equipment memory. The encryption method and shared key used to store the
polynomial coefficients and the device ID can be selected by the manufacturer. Contact TI for information
regarding specifics for encryption of the device ID and CRC polynomial coefficients.
To authenticate a battery pack, the host reads the encrypted device ID and polynomial values. It decrypts those
values, then generates a 32-bit random challenge, which is transmitted to the bq26150. The bq26150 uses the
plain-text version of the polynomial coefficients and device ID, along with the 32-bit random challenge from the
host, to calculate the authentication CRC value. The host uses the polynomial coefficients and device ID that it
decrypted, along with the 32-bit random challenge it sent to the bq26150, to calculate the authentication CRC
value. When the host and bq26150 have completed the calculations, the host can read the authentication CRC
value the bq26150 computed and compare to its own value. If the values match, the battery pack is
authenticated.
The bq26150 has a communication pass-through mode that allows it to be used in systems with an existing HDQ
based battery monitor or gas gauge. Once the battery pack is authenticated, the bq26150 can be put in
continuous pass-through mode, allowing the host system to communicate with a second HDQ device with no
additional overhead. A one-time pass-through mode is also available, allowing the host to communicate once to
the second HDQ device as needed.
The bq26150 obtains the power needed to run from the HDQ bus. An external capacitor is charged when the bus
is high and discharges while the bus is low. If the bq26150 is not authenticating or communicating, the power is
reduced and it enters sleep mode. If the bus is held low, the capacitor fully discharges and the bq26150 is
disabled.
3
IMPORTANT NOTICE
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enhancements, improvements, and other changes to its products and services at any time and to discontinue
any product or service without notice. Customers should obtain the latest relevant information before placing
orders and should verify that such information is current and complete. All products are sold subject to TI's terms
and conditions of sale supplied at the time of order acknowledgment.
TI warrants performance of its hardware products to the specifications applicable at the time of sale in
accordance with TI's standard warranty. Testing and other quality control techniques are used to the extent TI
deems necessary to support this warranty. Except where mandated by government requirements, testing of all
parameters of each product is not necessarily performed.
TI assumes no liability for applications assistance or customer product design. Customers are responsible for
their products and applications using TI components. To minimize the risks associated with customer products
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Following are URLs where you can obtain information on other Texas Instruments products and application
solutions:
Products
Applications
Amplifiers
amplifier.ti.com
Audio
www.ti.com/audio
Data Converters
dataconverter.ti.com
Automotive
www.ti.com/automotive
DSP
dsp.ti.com
Broadband
www.ti.com/broadband
Interface
interface.ti.com
Digital Control
www.ti.com/digitalcontrol
Logic
logic.ti.com
Military
www.ti.com/military
Power Mgmt
power.ti.com
Optical Networking
www.ti.com/opticalnetwork
Microcontrollers
microcontroller.ti.com
Security
www.ti.com/security
Telephony
www.ti.com/telephony
Video & Imaging
www.ti.com/video
Wireless
www.ti.com/wireless
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Texas Instruments
Post Office Box 655303 Dallas, Texas 75265
Copyright
2005, Texas Instruments Incorporated
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