Cymbet CBC34123-M5C-TR5 Spi real-time clock/calendar with integrated backup power Datasheet

Preliminary
CBC34123 EnerChip™ RTC
SPI Real-Time Clock/Calendar with Integrated Backup Power
Features
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Integrated rechargeable solid state battery with
power-fail detect and automatic switchover, providing greater than 30 hours of RTC backup
Smallest commercially available RTC with integrated backup power in compact 5mm x 5mm
1.4mm QFN package
Temperature compensated charge control
Integrated EnerChip™ recharged at VDD > 2.5V
SMT assembly - lead-free reflow solder tolerant
Real time clock provides year, month, day, weekday, hours, minutes, and seconds based on a
32.768 kHz quartz crystal
Resolution: seconds to years
Watchdog functionality
Freely programmable timer and alarm with interrupt capability
3-line SPI-bus with separate, but combinable
data input and output
Integrated oscillator load capacitors for CL = 7 pF
Internal Power-On Reset (POR)
Open-drain interrupt and clock output pins
Programmable offset register for frequency
adjustment
Eco-friendly, RoHS compliant - tested
Applications
Wireless sensors and RFID tags and other
powered, low duty cycle applications.
• Power bridging to provide uninterruptible RTC
function during exchange of main batteries.
• Consumer appliances that have real-time
clocks; provides switchover power from main
supply to backup battery.
• Business and industrial systems such as:
network routers, point-of-sale terminals, singleboard computers, test equipment, multi-function
printers, industrial controllers, and utility meters.
• Time keeping application
• Battery powered devices
• Metering
• High duration timers
• Daily alarms
• Low standby power applications
•
5mm x 5mm x 1.4mm 16-QFN Package
General Description
The EnerChip RTC CBC34123-M5C combines a
Real-Time Clock (RTC) and calendar optimized
for low power applications with an integrated
rechargeable solid state backup battery and all power
management functions. The EnerChip RTC ensures
a seamless transition from main power to backup
power in the event of power loss. The integrated
power management circuit ensures thousands of
charge-discharge cycles from the integrated EnerChip
and manages battery charging, discharge cutoff,
power switchover, and temperature compensation
to maximize the service life of the device. The
CBC34123 provides greater than 30 hours of backup
time in the event main power is interrupted. Typical
blackout times are less than 4 hours. The EnerChip
has extremely low self-discharge, recharges quickly, is
non-flammable, and RoHS-compliant. The EnerChip is
charged automatically anytime VDD is above 2.5V.
Data is transferred serially via a Serial Peripheral
Interface (SPI-bus) with a maximum data rate of 6.25
Mbit/s. Alarm and timer functions provide the option
to generate a wake-up signal on an interrupt pin. An
offset register allows fine tuning of the clock.
Figure 1: CBC34123 Pin-out Diagram
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Preliminary
CBC34123 EnerChip™ RTC
16
OSCI
1
OSCO
OSCILLATOR
32.768 kHz
DIVIDER
CLOCKOUT
CLKOE
11
CLKOUT
12
INT
3
MONITOR
OFFSET FUNCTION
0Dh
6
VCHG
7
VEC
14 RESET
15
ENERCHIP
AND
CHARGER
Offset_register
TIMER FUNCTION
0Eh
Timer_clkout
0Fh
Countdown_timer
EN
CONTROL
2
TEST
13
VDD
5
VSS
POWERON
RESET
WATCH
DOG
8
SDO
9
SDI
10
SCL
4
CE
SPI
INTERFACE
00h
Control_1
01h
Control_2
02h
Seconds
03h
Minutes
04h
Hours
TIME
05h
Days
06h
Weekdays
07h
Months
08h
Years
ALARM FUNCTION
09h
Minute_alarm
0Ah
Hour_alarm
0Bh
Day_alarm
0Ch
Weekday_alarm
INTERRUPT
Figure 2: CBC34123 Block Diagram with Registers
Figure 3: Internal Schematic of CBC34123 EnerChip RTC
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Preliminary
CBC34123 EnerChip™ RTC
CBC34123 Input/Output Descriptions
Pin Number
Label
Description
1
OSCO
Oscillator output; high-impedance node; minimize wire length between
quartz and package
2
TEST
Test pin; not user accessible; connect to VSS or leave floating (internally
pulled down)
3
INT/
Interrupt output (open-drain; active LOW)
4
CE
Chip enable input (active HIGH) with internal pull down
5
VSS
Ground
6
VCHG
4.1V (typical) charging source - connect to VBAT and/or optional EnerChip(s)
7
VEC
Positive terminal of integrated thin film battery - connect to VCHG and nothing else
8
SDO
Serial data output, push-pull; high-impedance when not driving; can be connected to SDI for single wire data line
9
SDI
Serial data input; may float when CE is inactive
10
SCL
Serial clock input; may float when CE is inactive
11
CLKOE
CLKOUT enable or disable pin; enable is active HIGH; connect to VSS for low
power operation
12
CLKOUT
Clock output (open-drain)
13
VDD
Supply voltage; positive or negative steps in VDD can affect oscillator performance; recommend 100nF decoupling close to the device (see Fig. 30)
14
RESET/
Output signal indicating RTC is operating in backup power mode
15
EN
Charge pump enable; activates VCHG 4.1V (typ.) charging source
OSCI
Oscillator input; high-impedance node; minimize wire length between quartz
and package
16
Package
Dimensions
(mm)
Figure 4: CBC34123 Package (left: top view, looking through package; right: pad dimensions)
EnerChip Properties
Energy capacity (typical): Recharge time to 80%:
Charge/discharge cycles: Operating temperature:
Storage temperature:
Minimum VDD to charge EnerChip:
5µAh
10 minutes
>5000 to 10% depth-of-discharge
-20°C to +70°C
-40°C to +125°C
2.5V
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Preliminary
CBC34123 EnerChip™ RTC
Absolute Maximum Ratings
PARAMETER / PIN
CONDITION
MIN
TYPICAL
MAX
UNITS
VDD with respect to GND
25°C
GND - 0.3
-
6.0
V
ENABLE Input Voltage
25°C
GND - 0.3
-
VDD+0.3
V
VEC
25°C
3.0
-
4.15
V
25°C
3.0
-
4.15
V
25°C
GND - 0.3
-
2.7
V
(1)
VCHG
(1)
RESET Output Voltage
INT/, CE, TEST, OSCI, OSCO, SDO,
SDI, SCL, CLKOE, CLKOUT
(1)
See NXP PCF2123 Data Sheet
No external connections to these pins are allowed, except parallel EnerChips.
Integrated EnerChip Thin Film Battery Operating Characteristics
PARAMETER
CONDITION
MIN
TYPICAL
MAX
UNITS
Non-recoverable
-
2.5
-
% per year
Recoverable
-
1.5
-
% per year
Operating Temperature
-
-20
25
+70
°C
Storage Temperature
-
-40
-
+125 (2)
°C
10% depth-of-discharge
5000
-
-
cycles
50% depth-of discharge
1000
-
-
cycles
Self-Discharge (5 yr. average)
25°C
Recharge Cycles
(to 80% of rated
capacity)
40°C
Recharge Time (to 80% of rated
capacity; 4.1V charge; 25°C)
Capacity (see Figure 5)
(1)
10% depth-of-discharge
2500
-
-
cycles
50% depth-of-discharge
500
-
-
cycles
Charge cycle 2
-
11
22
Charge cycle 1000
-
45
70
25°C
5
-
-
(1)
First month recoverable self-discharge is 5% average.
(2)
Storage temperature is for uncharged EnerChip CC device.
minutes
µAh
Figure 5: Typical Discharge Characteristics of the CBC005 EnerChip Within the CBC34123
Note: All specifications contained within this document are subject to change without notice.
©2012 Cymbet Corporation • Tel: +1-763-633-1780 • www.cymbet.com
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Preliminary
CBC34123 EnerChip™ RTC
Important Reference Documents
For complete specifications of the integrated PCF2123 Real-Time Clock, see here:
http://www.nxp.com/documents/data_sheet/PCF2123.pdf .
For complete specifications of the Cymbet 5µAh EnerChip and integrated power management circuit, see here:
http://www.cymbet.com/pdfs/DS-72-21.pdf .
The EnerChip and power management functions within the CBC34123 are configured as in Mode 1 (VMODE =
GND) described in the CBC3105 data sheet.
For guidelines regarding crystal selection and other important information pertaining to the PCF2123, see the
UM10301 - User Manual for NXP Real Time Clocks, located here:
http://www.nxp.com/documents/user_manual/UM10301.pdf
Functional Description of Integrated PCF2123 Real-Time Clock
The PCF2123 contains 16 8-bit registers with an auto-incrementing address counter, an on-chip 32.768 kHz
oscillator with two integrated load capacitors, a frequency divider which provides the source clock for the Real
Time Clock (RTC), a programmable clock output, and a 6.25 Mbit/s SPI-bus. An offset register allows fine tuning
of the clock.
All 16 registers are designed as addressable 8-bit parallel registers although not all bits are implemented.
• The first two registers (memory address 00h and 01h) are used as control registers.
• The memory addresses 02h through 08h are used as counters for the clock function (seconds up to years). The
registers Seconds, Minutes, Hours, Days, Weekdays, Months, and Years are all coded in Binary Coded
Decimal (BCD) format. When one of the RTC registers is written or read the contents of all counters are
frozen. Therefore, faulty writing or reading of the clock and calendar during a carry condition is prevented.
• Addresses 09h through 0Ch define the alarm condition.
• Address 0Dh defines the offset calibration.
• Address 0Eh defines the clock out and timer mode.
• Address registers 0Eh and 0Fh are used for the countdown timer function. The countdown timer has four
selectable source clocks allowing for countdown periods in the range from 244 ms up to four hours. There
are also two pre-defined timers which can be used to generate an interrupt once per second or once per
minute. These are defined in register Control_2 (01h).
Low Power Operation
Minimum power operation will be achieved by reducing the number and frequency of switching signals inside the
IC, i.e., low frequency timer clocks and a low frequency CLKOUT will result in lower operating power. A second
prime consideration is the series resistance Rs of the quartz used.
Power Consumption with Respect to Quartz Series Resistance
The series resistance acts as a loss element. Low RS will reduce current consumption further.
©2012 Cymbet Corporation • Tel: +1-763-633-1780 • www.cymbet.com
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Preliminary
CBC34123 EnerChip™ RTC
PCF2123 Register Overview
16 registers are available. The time registers are encoded in the Binary Coded Decimal (BCD) format to simplify
application use. Other registers are either bit-wise or standard binary.
Bit positions labeled as ‘-’ are not implemented and will return a ‘0’ when read. The bit position labeled as ‘--’ is
not implemented and will return a ‘0’ or ‘1’ when read. Bit positions labeled with N should always be written with
logic ‘0’ (1).
Address
Register name
Bit
7
6
5
4
3
2
1
0
Control and status registers
00h
Control_1
EXT_TEST N
STOP
SR
N
12_24
CIE
N
01h
Control_2
MI
SI
MSF
TI_TP
AF
TF
AIE
TIE
Time and date registers
02h
Seconds
OS
SECONDS (0 to 59)
03h
Minutes
--
MINUTES (0 to 59)
04h
Hours
-
-
AMPM
HOURS (1 to 12) in 12 h mode
HOURS (0 to 23) in 24 h mode
05h
Days
-
-
DAYS (1 to 31)
06h
Weekdays
-
-
-
-
07h
Months
-
-
-
MONTHS (1 to 12)
08h
Years
YEARS (0 to 99)
-
WEEKDAYS (0 to 6)
Alarm registers
09h
Minute_alarm
AE_M
MINUTE_ALARM (0 to 59)
0Ah
Hour_alarm
AE_H
-
AMPM
HOUR_ALARM (1 to 12) in 12 h mode
HOUR_ALARM (0 to 23) in 24 h mode
0Bh
Day_alarm
AE_D
-
DAY_ALARM (1 to 31)
0Ch
Weekday_alarm
AE_W
-
-
MODE
OFFSET[6:0]
COF[2:0]
-
-
WEEKDAY_ALARM (0 to
6)
TE
-
Offset register
0Dh
Offset_register
Timer registers
0Eh
Timer_clkout
-
0Fh
Countdown_timer
COUNTDOWN_TIMER[7:0]
[1]
CTD[1:0]
Except in the case of software reset, see Section 8.3.1.1.
©2012 Cymbet Corporation • Tel: +1-763-633-1780 • www.cymbet.com
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Preliminary
CBC34123 EnerChip™ RTC
POWER SUPPLY CURRENT CHARACTERISTICS OF INTEGRATED CBC910 POWER
MANAGEMENT CIRCUIT ONLY
Ta = -20ºC to +70ºC
CHARACTERISTIC
Quiescent Current
(CBC910 power
management circuit
only; VDD > VRESET ; RTC
current not included)
EnerChip Cutoff Current
(IQBATON adds to RTC
current when in backup
mode)
SYMBOL
CONDITION
ENABLE=GND
IQ
ENABLE=VDD
MIN
MAX
UNITS
VDD=3.3V
-
3.5
µA
VDD=5.5V
-
6.0
µA
VDD=3.3V
-
35
µA
VDD=5.5V
-
38
µA
IQBATOFF
VBAT < VBATCO,
VOUT=0
-
0.5
nA
IQBATON
VBAT > VBATCO,
ENABLE=VDD, IOUT=0
-
42
nA
INTERFACE LOGIC SIGNAL CHARACTERISTICS
VDD = 2.5V to 5.5V, Ta = -20ºC to +70ºC
CHARACTERISTIC
SYMBOL
CONDITION
MIN
MAX
UNITS
High Level Input Voltage
VIH
-
VDD - 0.5
-
Volts
Low Level Input Voltage
VIL
-
-
0.5
Volts
VDD 0.04V (1)
-
Volts
High Level Output Voltage
VOH
VDD>VTH (see Figures 4
and 5) IL=10µA
Low Level Output Voltage
VOL
IL = -100µA
-
0.3
Volts
Logic Input Leakage Current
IIN
0<VIN<VDD
-1.0
+1.0
nA
(1)
RESET tracks VDD; RESET = VDD - (IOUT x ROUT).
RESET SIGNAL AC/DC CHARACTERISTICS
VDD = 2.5V to 5.5V, Ta = -20ºC to +70ºC
CHARACTERISTIC
SYMBOL
CONDITION
MIN
MAX
UNITS
VDD Rising to RESET
Rising
tRESETH
VDD rising from 2.8V TO 3.1V
in <10µs
60
200
ms
VDD Falling to RESET
Falling
tRESETL
VDD falling from 3.1V to 2.8V
in <100ns
0.5
2
µs
TRIP Voltage
VDD Rising
VRESET
VMODE=GND
2.85
3.15
V
RESET Hysteresis
Voltage
(VDD to RESET)
VHYST
VMODE=GND
45
75
mV
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Preliminary
CBC34123 EnerChip™ RTC
CHARGE PUMP CHARACTERISTICS (PERTAINS TO INTEGRATED CBC910 POWER MANAGEMENT CIRCUIT)
(NOTE: THIS TABLE PROVIDES IMPORTANT INFORMATION WHEN CONNECTING ADDITIONAL ENERCHIPS TO VCHG.)
VDD = 2.5V to 5.5V, Ta = -20ºC to +70ºC
CHARACTERISTIC
SYMBOL
ENABLE=VDD to Charge
Pump Active
tCPON
ENABLE Falling to
Charge Pump Inactive
tCPOFF
CONDITION
MIN
MAX
UNITS
60
80
µs
0
1
µs
-
120
KHz (1)
150
300
Ω
ENABLE to 3rd charge pump
pulse, VDD=3.3V
-
Charge Pump Frequency
fCP
Charge Pump
Resistance
RCP
Delta VBAT, for IBAT charging
current of 1µA to 100µA
CFLY=0.1µF, CBAT=1.0µF
VCHG Output Voltage
VCP
CFLY=0.1µF, CBAT=1.0µF,
IOUT=1µA, Temp=+25ºC
4.075
4.125
V
VCHG Temp. Coefficient
TCCP
IOUT=1µA, Temp=+25ºC
-2.0
-2.4
mV/ºC
ICP
IBAT=1mA
CFLY=0.1µF, CBAT=1.0µF
1.0
-
mA
ENABLE=VDD
2.5
-
V
Charge Pump Current
Drive
Charge Pump on Voltage
(1)
VENABLE
fCP = 1/tCPPER
ADDITIONAL CHARACTERISTICS
Ta = -20ºC to +70ºC
CHARACTERISTIC
VBAT Cutoff Threshold
SYMBOL
VBATCO
Cutoff Temp. Coefficient
TCCO
VBAT Cutoff Delay Time
tCOOFF
CONDITION
LIMITS
UNITS
MIN
MAX
2.75
3.25
V
+1
+2
mV/ºC
40
-
ms
IOUT=1µA
VBAT from 40mV above to
20mV below VBATCO
IOUT=1µA
Note: All specifications contained within this document are subject to change without notice
©2012 Cymbet Corporation • Tel: +1-763-633-1780 • www.cymbet.com
DS-72-31 V.08
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Preliminary
CBC34123 EnerChip™ RTC
Ordering Information
EnerChip CC Part Number
Description
Notes
CBC34123-M5C
EnerChip RTC in 5mm x 5mm x
1.4mm 16-QFN Land Grid Array
Shipped in Tube
CBC34123-M5C-TR1
CBC34123-M5C-TR5
EnerChip RTC in 5mm x 5mm x
1.4mm 16-QFN Land Grid Array
Tape-and-Reel - 1000 pcs (TR1) or
5000 pcs (TR5) per reel
CBC-EVAL-12
EnerChip RTC Evaluation Kit
USB based Eval Kit with
CBC34123 tab board
U.S. Patent No. 8,144,508. Additional U.S. and Foreign Patents Pending
Disclaimer of Warranties; As Is
The information provided in this data sheet is provided “As Is” and Cymbet Corporation disclaims all representations or warranties of any
kind, express or implied, relating to this data sheet and the Cymbet EnerChip product described herein, including without limitation, the
implied warranties of merchantability, fitness for a particular purpose, non-infringement, title, or any warranties arising out of course of
dealing, course of performance, or usage of trade. Cymbet EnerChip products are not authorized for use in life critical applications. Users
shall confirm suitability of the Cymbet EnerChip product in any products or applications in which the Cymbet EnerChip product is adopted
for use and are solely responsible for all legal, regulatory, and safety-related requirements concerning their products and applications and
any use of the Cymbet EnerChip product described herein in any such product or applications.
Cymbet, the Cymbet Logo, and EnerChip are Cymbet Corporation Trademarks
©2012 Cymbet Corporation • Tel: +1-763-633-1780 • www.cymbet.com
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