DS1212 ,Nonvolatile Controller x 16 ChipPIN DESCRIPTION7 23CE13 CE2A, B, C, D - Address Inputs 8 22CE12 CE39 21CE11 CE4CE - Chip Enable10 2 ..
DS1213B ,SmartSocket 16k/64kPIN DESCRIPTIONCE - Conditioned Chip EnableV - Switched VCC CCGND - GroundAll pins pass through exc ..
DS1213C ,SmartSocket 256kFEATURES PIN ASSIGNMENT Accepts standard 32K x 8 CMOS static128 VCCRAMs2 27 Embedded lithium ..
DS1213-C ,SmartSocket 256kDS1213CSmartSocket 256kwww.dalsemi.com
DS1213D ,SmartSocket 256k/1MFEATURES PIN ASSIGNMENT Accepts standard 32K x 8 or 128K x 8132 VCCCMOS static RAMs2 31 Embed ..
DS1213D ,SmartSocket 256k/1MFEATURES PIN ASSIGNMENT Accepts standard 32K x 8 or 128K x 8132 VCCCMOS static RAMs2 31 Embed ..
DTA114TK , DTA/DTC SERIES
DTA114TM , Built-In Bias Resistors Enable The Configuration of An Inverter Circuit Without Connecting External Input Resistors
DTA114TS , DTA/DTC SERIES
DTA114TS , DTA/DTC SERIES
DTA114WE , -100mA / -50V Digital transistors (with built-in resistors)
DTA114WUA , -100mA / -50V Digital transistors (with built-in resistors)
DS1212
Nonvolatile Controller x 16 Chip
FEATURESConverts full CMOS RAM into nonvolatile
memoryUnconditionally write protects when VCC isout of toleranceAutomatically switches to battery when
power-fail occurs4 to 16 decoder provides control for up to 16
CMOS RAMsConsumes less than 100 nA of battery
currentTests battery condition on power-upProvides for redundant batteriesPower fail signal can be used to interruptprocessor on power failureOptional 5% or 10% power-fail detectionOptional 28-pin PLCC surface mount
packageOptional industrial temperature range of-40°C to +85°C
PIN DESCRIPTIONA, B, C, D - Address Inputs - Chip Enable
CE0-CE15- Chip Enable Outputs
GND- Ground
VBAT1- + Battery 1VBAT2- + Battery 2
TOL- Power Supply Tolerance
VCCI- +5V Supply
VCCO- RAM Supply- Power Fail
PIN ASSIGNMENT
DESCRIPTIONThe DS1212 Nonvolatile Controller x16 Chip is a CMOS circuit that solves the application problem of
converting CMOS RAMs into nonvolatile memories. Incoming power is monitored for an out-of-
tolerance condition. When such a condition is detected, the chip enables are inhibited to accomplish write
protection and the battery is switched on to supply the RAMs with uninterrupted power. Special circuitry
uses a low-leakage CMOS process that affords precise voltage detection at extremely low battery
DS1212
Nonvolatile Controller x 16 ChipVBAT1
VCCO
TOL
CE15
CE14
CE13
CE12
CE11
GND
VCCI
VBAT2
CE0
CE1
CE2
CE3
CE4
CE5
CE6
CE7
CE8
CE9
CE10
28-Pin DIP (600-mil)
See Mech. Drawings Section
28-Pin PLCC
See Mech. Drawings Section
CE15
CE14
CE13
CE12
CE11TOLVC
AT1
AT2
12 13 14 15 16 17 18
CE0
CE1
CE2
CE3
CE4
CE5
CE6
GND
DS1212
By combining the DS1212 Nonvolatile Controller chip and lithium batteries, nonvolatile RAM operation
can be achieved for up to 16 CMOS memories.
OPERATIONThe DS1212 performs six circuit functions required to decode and battery back up a bank of up to 16
RAMs. First, the 4-to-16 decoder provides selection of one of 16 RAMs. Second, a switch is provided todirect power from the battery or VCCI supply, depending on which is greater. This switch has a voltage
drop of less than 0.2V. The third function the DS1212 provides is power-fail detection. It constantly
monitors the VCCI supply. When VCCI falls below 4.75 volts or 4.5 volts, depending on the level of
tolerance Pin 3, a precision comparator outputs a power-fail detect signal to the decoder/chip enable logic
and the PF signal is driven low. The PF signal will remain low until VCCI is back in normal limits.
The fourth function of write protection is accomplished by holding all chip enable outputs (CE0-CE15) to
within 0.2 volts of VCCI or battery supply. If CE is low at the time power fail detection occurs, the chip
enable outputs are kept in their present state until CE is driven high. The delay of write protection until
the current memory cycle is completed prevents corruption of data. Power-fail detection occurs in the
range of 4.75 volts to 4.5 volts with tolerance Pin 3 grounded. If Pin 3 is connected to VCCO, then power-
fail occurs in the range of 4.5 volts to 4.25 volts. During nominal supply conditions the chip enableoutputs follow the logic of a 4-to-16 decoder, shown in Figure 1.
The fifth function the DS1212 performs is a battery status warning so that data loss is avoided. Each time
the circuit is powered up, the battery voltage is checked with a precision comparator. If the battery
voltage is less than 2 volts, the second memory cycle is inhibited. Battery status can, therefore, bedetermined by performing a read cycle after power-up to any location in memory, verifying that memory
location content. A subsequent write cycle can then be executed to the same memory location, altering the
data. If the next read cycle fails to verify the written data, then the batteries are less than 2.0 volts and
data is in danger of being corrupted.
The sixth function of the DS1212 provides for battery redundancy. In many applications, data integrity is
paramount. In these applications it is often desirable to use two batteries to ensure reliability. The
DS1212 provides an internal isolation switch which allows the connection of two batteries during battery
backup operation. The battery with the highest voltage is selected for use. If one battery should fail, the
other will then assume the load. The switch to a redundant battery is transparent to circuit operation andthe user. A battery status warning will only occur if both batteries are less than 2.0 volts. For single
battery applications the unused battery input must be grounded.
DS1212
NONVOLATILE CONTROLLER/DECODER Figure 1H = High LevelL = Low Level
X = Irrelevant
Note: VCCI input is 250 mV lower when TOL PIN3 = VCCO.
DS1212
ABSOLUTE MAXIMUM RATINGS*Voltage on Any Pin Relative to Ground-0.3V to +7.0V
Operating Temperature0°C to 70°C
Storage Temperature-55°C to +125°C
Soldering Temperature260°C for 10 secondsThis is a stress rating only and functional operation of the device at these or any other conditions
above those indicated in the operation sections of this specification is not implied. Exposure to
absolute maximum rating conditions for extended periods of time may affect reliability.
RECOMMENDED DC OPERATING CONDITIONS(0°C to 70°C)
(0°C to 70°C; VCCI = 4.75 to 5.5V PIN 3 = GND)
(0°C to 70°C; VCCI = 4.5 to 5.5V, PIN 3 = VCCO)
DC ELECTRICAL CHARACTERISTICS(0°C to 70°C; VCCI < VBAT)
DS1212
CAPACITANCE(TA = 25°C)
(0°C to 70°C; VCCI = 4.75 to 5.5V, PIN 3 = GND)
(0°C to 70°C; VCCI = 4.5 to 5.5V, PIN 3 = VCCO)
AC ELECTRICAL CHARACTERISTICS(0°C to 70°C; VCCI < 4.75V, PIN 3 = GND)
(0°C to 70°C; VCCI < 4.5V, PIN 3 = VCCO)
DS1212
TIMING DIAGRAM: DECODER
TIMING DIAGRAM: POWER-UP
TIMING DIAGRAM: POWER-DOWN
