CATALYST CAT514

CAT514
8-Bit Quad Digital POT
FEATURES
APPLICATIONS
■ Output settings retained without power
■ Automated product calibration.
■ Output range includes both supply rails
■ Remote control adjustment of equipment
■ 4 independently addressable outputs
■ Offset, gain and zero adjustments in Self-
Calibrating and Adaptive Control systems.
■ 1 LSB Accuracy
■ Tamper-proof calibrations.
■ Serial µP interface
■ Single supply operation: 2.7V-5.5V
■ Setting read-back without effecting outputs
DESCRIPTION
The CAT514 is a quad 8-Bit Memory DAC designed as
an electronic replacement for mechanical potentiometers and trim pots. Intended for final calibration of
products such as camcorders, fax machines and cellular
telephones on automated high volume production lines,
it is also well suited for systems capable of self calibration, and applications where equipment which is either
difficult to access or in a hazardous environment, requires periodic adjustment.
Control of the CAT514 is accomplished with a simple 3
wire serial interface. A Chip Select pin allows several
CAT514's to share a common serial interface and communication back to the host controller is via a single
serial data line thanks to the CAT514’s Tri-Stated Data
Output pin. A Rdy/Bsy output working in concert with an
internal low voltage detector signals proper operation of
EEPROM Erase/Write cycle.
The CAT514 is available in the 0 to 70° C Commercial
and –40° C to + 85° C Industrial operating temperature
ranges and offered in 14-pin plastic DIP and SOIC
packages.
The 4 independently programmable DAC's have an
output range which includes both supply rails. Output
settings, stored in non-volatile EEPROM memory, are
not lost when the device is powered down and are
automatically reinstated when power is returned. Each
output can be dithered to test new output values without
effecting the stored settings and stored settings can be
read back without disturbing the DAC’s output.
FUNCTIONAL DIAGRAM
RDY/BSY
3
PROG
7
PIN CONFIGURATION
VDD
VREF H
1
DIP Package (P)
PROGRAM
CONTROL
DAC 1
DI
CLK
CS
5
DAC 2
2
SERIAL
CONTROL
SOIC Package (J)
14
13
12
VOUT 1
VDD
1
14
CLK
RDY/BSY
2
13
CS
4
DI
DO
VOUT 2
DATA
REGISTER
& EEPROM
PROG
DAC 3
4
DAC 4
SERIAL
DATA
OUTPUT
REGISTER
11
10
6
3
12
CAT
11
514
5
10
6
9
7
8
VDD
VREFH
CLK
VOUT1
VOUT2 RDY/BSY
VOUT3
VOUT4
VREFL
GND
CS
DI
DO
PROG
12
4 CAT 11
514
5
10
6
9
VREFH
VOUT1
VOUT2
VOUT3
VOUT4
VREFL
7
GND
1
14
2
13
3
8
VOUT 3
VOUT 4
DO
CAT514
8
GND
© 2000 by Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
9
V
L
REF
1
Doc. No. 25075-00 2/98 M-1
CAT514
ABSOLUTE MAXIMUM RATINGS*
Junction Temperature ..................................... +150°C
Storage Temperature ....................... –65°C to +150°C
Lead Soldering (10 sec max) .......................... +300°C
Supply Voltage
VDD to GND ...................................... –0.5V to +7V
Inputs
CLK to GND ............................ –0.5V to VDD +0.5V
CS to GND .............................. –0.5V to VDD +0.5V
DI to GND ............................... –0.5V to VDD +0.5V
PROG to GND ........................ –0.5V to VDD +0.5V
VREFH to GND ........................ –0.5V to VDD +0.5V
VREFL to GND ......................... –0.5V to VDD +0.5V
Outputs
D0 to GND ............................... –0.5V to VDD +0.5V
VOUT 1– 4 to GND ................... –0.5V to VDD +0.5V
Operating Ambient Temperature
Commercial (‘C’ suffix) .................... 0°C to +70°C
Industrial (‘I’ suffix) ...................... – 40°C to +85°C
* Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Absolute
Maximum Ratings are limited values applied individually while
other parameters are within specified operating conditions,
and functional operation at any of these conditions is NOT
implied. Device performance and reliability may be impaired by
exposure to absolute rating conditions for extended periods of
time.
RELIABILITY CHARACTERISTICS
Symbol
Parameter
Min
VZAP(1)
ILTH(1)(2)
ESD Susceptibility
Latch-Up
2000
100
Notes:
Max
Units
Test Method
Volts
mA
MIL-STD-883, Test Method 3015
JEDEC Standard 17
1. This parameter is tested initially and after a design or process change that affects the parameter.
2. Latch-up protection is provided for stresses up to 100mA on address and data pins from –1V to VCC + 1V.
DC ELECTRICAL CHARACTERISTICS:
VDD = +2.7 to +5.5V, VREFH = VDD, VREFL = 0V, unless otherwise specified
Symbol
Parameter
Conditions
Min
Typ
Max
8
—
—
Bits
ILOAD = 250 nA, TR = C
TR = I
ILOAD = 1 µA,
TR = C
TR = I
ILOAD = 250 nA, TR = C
TR = I
ILOAD = 1 µA,
TR = C
TR = I
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
±1
±1
±2
±2
± 0.5
± 0.5
± 1.5
± 1.5
LSB
LSB
LSB
LSB
LSB
LSB
LSB
LSB
VIN = VDD
VIN = 0V
—
—
2
0
—
—
—
—
10
–10
VDD
0.8
µA
µA
V
V
2.7
GND
—
—
—
7k
VDD
VDD -2.7
—
V
V
Ω
VDD –0.3
—
—
—
—
0.4
V
V
—
—
0.4
V
Resolution
Units
Accuracy
INL
Integral Linearity Error
DNL
Differential Linearity Error
Logic Inputs
IIH
IIL
VIH
VIL
Input Leakage Current
Input Leakage Current
High Level Input Voltage
Low Level Input Voltage
References
VRH
VRL
ZIN
VREFH Input Voltage Range
VREFL Input Voltage Range
VREFH–VREFL Resistance
Logic Outputs
VOH
VOL
High Level Output Voltage
Low Level Output Voltage
IOH = – 40 µA
IOL = 1 mA, VDD = +5V
IOL = 0.4 mA, VDD = +3V
Doc. No. 25075-00 2/98 M-1
2
CAT514
DC ELECTRICAL CHARACTERISTICS (Cont.):
VDD = +2.7V to +5.5V , VREFH = +VDD, VREFL = 0V, unless otherwise specified
Symbol
Parameter
Conditions
Min
Typ
Max
Units
0.99 VR
—
—
—
—
—
0.995 VR
0.005 VR
—
—
—
—
—
0.01 VR
1
100k
150k
1
V
V
µA
Ω
Ω
LSB / V
VREFH = +5V, VREFL = 0V
—
—
200
µV/ °C
VDD = +5V, ILOAD = 250nA
VREFH to VREFL
—
700
—
—
—
—
2.7
40
1200
600
—
50
2000
1200
5.5
µA
µA
µA
V
Min
Typ
Max
Units
150
100
0
50
50
—
—
—
—
—
700
150
500
300
DC
—
—
—
—
—
—
—
400
4
400
—
—
—
—
—
—
—
—
—
—
150
150
—
5
—
—
—
—
—
1
ns
ns
ns
ns
ns
ns
ns
ns
ms
ns
ns
ns
ns
ns
MHz
CLOAD = 10 pF, VDD = +5V
CLOAD = 10 pF, VDD = +3V
—
—
3
6
10
10
µs
µs
VIN = 0V, f = 1 MHz(2)
VOUT = 0V, f = 1 MHz(2)
—
—
8
6
—
—
pF
pF
Analog Output
FSO
ZSO
IL
ROUT
Full-Scale Output Voltage
Zero-Scale Output Voltage
DAC Output Load Current
DAC Output Impedance
PSSR
Power Supply Rejection
VR = VREFH–VREFL
VR = VREFH–VREFL
VDD = +5V
VDD = +3V
ILOAD = 250 nA
Temperature
TCO
VOUT Temperature Coefficient
TCREF
Temperature Coefficient of
VREF Resistance
ppm / °C
Power Supply
IDD1
IDD2
Supply Current (Read)
Supply Current (Write)
VDD
Operating Voltage Range
Normal Operating
VDD=5V
VDD=3V
AC ELECTRICAL CHARACTERISTICS:
VDD = +2.7V to +5.5V, VREFH = +VDD, VREFL = 0V, unless otherwise specified
Symbol
Parameter
Conditions
Digital
tCSMIN
tCSS
tCSH
tDIS
tDIH
tDO1
tDO0
tHZ
tBUSY
tLZ
tPROG
tPS
tCLKH
tCLKL
fC
Minimum CS Low Time
CS Setup Time
CS Hold Time
DI Setup Time
DI Hold Time
Output Delay to 1
Output Delay to 0
Output Delay to High-Z
Erase/Write Cycle Time
Output Delay to Low-Z
Erase/Write Pulse Width
PROG Setup Time
Minimum CLK High Time
Minimum CLK Low Time
Clock Frequency
CL = 100 pF
see note 1
Analog
tDS
DAC Settling Time to 1/2 LSB
Pin Capacitance
CIN
COUT
Notes:
Input Capacitance
Output Capacitance
1. All timing measurements are defined at the point of signal crossing VDD / 2.
2. These parameters are periodically sampled and are not 100% tested.
3
Doc. No. 25075-00 2/98 M-1
2
3
4
5
t CLK H
PARAM
NAME
TIMING
MIN/MAX
FROM
TO
t CLK H Rising CLK edge to falling CLK edge
Min
t CLK L Falling CLK edge to CLK rising edge
Min
t CSH
Falling CLK edge for last data bit (DI)
to falling CS edge
Min
t CSS
Rising CS edge to next rising CLK edge
Min
CLK
t CSS
t CLK L
t CSH
CS
t CSMIN
t CSMIN Falling CS edge to rising CS edge
Min
t DIS
Data valid to first rising CLK
edge after CS = high
Min
t DIH
Rising CLK edge to end of data valid
Min
t DO0
Rising CLK edge to D0 = low
Max
t LZ
Rising CS edge to D0 becoming high
low impedance (active output)
(Max)
t DO1
Rising CLK edge to D0 = high
Max
t HZ
Falling CS edge to D0 becoming high
impedance (Tri-State)
(Max)
t PS
Rising PROG edge to next rising
CLK edge
t DIS
DI
4
t DIH
t DO0
t LZ
DO
t HZ
t DO1
PROG
t PS
t PROG
Min
t PROG Rising PROG edge to falling
PROG edge
Min
t BUSY Falling CLK edge after PROG=H to
rising RDY/BSY edge
Max
RDY/BSY
t BUSY
to
1
2
3
4
5
CAT514
1
A. C. TIMING DIAGRAM
Doc. No. 25075-00 2/98 M-1
to
CAT514
PIN DESCRIPTION
Pin
Name
1
2
3
4
5
6
7
VDD
CLK
RDY/BSY
CS
DI
DO
PROG
8
9
10
11
12
13
14
GND
VREFL
VOUT4
VOUT3
VOUT2
VOUT1
VREFH
DAC addressing is as follows:
Function
Power supply positive.
Clock input pin.Clock input pin.
Ready/Busy Output
Chip Select
Serial data input pin.
Serial data output pin.
EEPROM Programming Enable
Input
Power supply ground.
Minimum DAC output voltage.
DAC output channel 4.
DAC output channel 3.
DAC output channel 2.
DAC output channel 1.
Maximum DAC output voltage.
DEVICE OPERATION
DAC OUTPUT
A0
A1
VOUT1
0
0
VOUT2
1
0
VOUT3
0
1
VOUT4
1
1
read to or from the chip, and the Data Output (DO) pin is
active. Data loaded into the DAC control registers will
remain in effect until CS goes low. Bringing CS to a logic
low returns all DAC outputs to the settings stored in
EEPROM memory and switches DO to its high impedance Tri-State mode.
The CAT514 is a quad 8-bit Digital to Analog Converter
(DAC) whose outputs can be programmed to any one of
256 individual voltage steps. Once programmed, these
output settings are retained in non-volatile EEPROM
memory and will not be lost when power is removed from
the chip. Upon power up the DACs return to the settings
stored in EEPROM memory. Each DAC can be written
to and read from independently without effecting the
output voltage during the read or write cycle. Each
output can also be temporarily adjusted without changing the stored output setting, which is useful for testing
new output settings before storing them in memory.
Because CS functions like a reset the CS pin has been
equipped with a 30 ns to 90 ns filter circuit to prevent
noise spikes from causing unwanted resets and the loss
of volatile data.
CLOCK
The CAT514’s clock controls both data flow in and out of
the IC and EEPROM memory cell programming. Serial
data is shifted into the DI pin and out of the DO pin on the
clock’s rising edge. While it is not necessary for the clock
to be running between data transfers, the clock must be
operating in order to write to EEPROM memory, even
though the data being saved may already be resident in
the DAC control register.
DIGITAL INTERFACE
The CAT514 employs a standard 3 wire serial control
interface consisting of Clock (CLK), Chip Select (CS)
and Data In (DI) inputs. For all operations, address and
data are shifted in LSB first. In addition, all digital data
must be preceded by a logic “1” as a start bit. The DAC
address and data are clocked into the DI pin on the
clock’s rising edge. When sending multiple blocks of
information a minimum of two clock cycles is required
between the last block sent and the next start bit.
No clock is necessary upon system power-up. The
CAT514’s internal power-on reset circuitry loads data
from EEPROM to the DACs without using the external
clock.
Multiple devices may share a common input data line by
selectively activating the CS control of the desired IC.
Data Outputs (DO) can also share a common line
because the DO pin is Tri-Stated and returns to a high
impedance when not in use.
As data transfers are edge triggered clean clock transitions are necessary to avoid falsely clocking data into the
control registers. Standard CMOS and TTL logic families work well in this regard and it is recommended that
any mechanical switches used for breadboarding or
device evaluation purposes be debounced by a flip-flop
or other suitable debouncing circuit.
CHIP SELECT
Chip Select (CS) enables and disables the CAT514’s
read and write operations. When CS is high data may be
5
Doc. No. 25075-00 2/98 M-1
CAT514
complished through the control signals: Chip Select
(CS) and Program (PROG). With CS high, a start bit
followed by a two bit DAC address and eight data bits are
clocked into the DAC control register via the DI pin. Data
enters on the clock’s rising edge. The DAC output
changes to its new setting on the clock cycle following
D7, the last data bit.
VREF
VREF, the voltage applied between pins VREFH andVREFL,
sets the DAC’s Zero to Full Scale output range where
VREFL = Zero and VREFH = Full Scale. VREF can span the
full power supply range or just a fraction of it. In typical
applications VREFH andVREFL are connected across the
power supply rails. When using less than the full supply
voltage VREFH is restricted to voltages between VDD and
VDD/2 and VREFL to voltages between GND and VDD/2.
Programming is achieved by bringing PROG high for a
minimum of 3 ms. PROG must be brought high sometime after the start bit and at least 150 ns prior to the
rising edge of the clock cycle immediately following the
D7 bit. Two clock cycles after the D7 bit the DAC control
register will be ready to receive the next set of address
and data bits. The clock must be kept running throughout the programming cycle. Internal control circuitry
takes care of ramping the programming voltage for data
transfer to the EEPROM cells. The CAT514’s EEPROM
memory cells will endure over 100,000 write cycles and
will retain data for a minimum of 20 years without being
refreshed.
/BUSY
READY/BUSY
When saving data to non-volatile EEPROM memory, the
Ready/Busy ouput (RDY/BSY) signals the start and
duration of the EEPROM erase/write cycle. Upon receiving a command to store data (PROG goes high) RDY/
BSY goes low and remains low until the programming
cycle is complete. During this time the CAT514 will
ignore any data appearing at DI and no data will be
output on DO.
RDY/BSY is internally ANDed with a low voltage detector circuit monitoring VDD. If VDD is below the minimum
value required for EEPROM programming, RDY/BSY
will remain high following the program command indicating a failure to record the desired data in non-volatile
memory.
READING DATA
Each time data is transferred into a DAC control register
currently held data is shifted out via the D0 pin, thus in
every data transaction a read cycle occurs. Note,
however, that the reading process is destructive. Data
must be removed from the register in order to be read.
Figure 2 depicts a Read Only cycle in which no change
occurs in the DAC’s output. This feature allows µPs to
poll DACs for their current setting without disturbing the
output voltage but it assumes that the setting being read
is also stored in EEPROM so that it can be restored at the
end of the read cycle. In Figure 2 CS returns low before
the 13th clock cycle completes. In doing so the EEPROM’s
setting is reloaded into the DAC control register. Since
DATA OUTPUT
Data is output serially by the CAT514, LSB first, via the
Data Out (DO) pin following the reception of a start bit
and two address bits by the Data Input (DI). DO
becomes active whenever CS goes high and resumes
its high impedance Tri-State mode when CS returns low.
Tri-Stating the DO pin allows several 514s to share a
single serial data line and simplifies interfacing multiple
514s to a microprocessor.
WRITING TO MEMORY
Programming the CAT514’s EEPROM memory is acFigure 1. Writing to Memory
to
1
2
3
4
5
6
7
8
9
Figure 2. Reading from Memory
10
11
12
N
N+1 N+2
to
1
2
3
4
5
6
7
8
9
10
11
12
CS
CS
NEW DAC DATA
DI
1
A0
A1
D0
D1
D0
D1
D2
D3
D4
D5
D6
D7
D6
D7
DI
CURRENT DAC DATA
DO
D2
D3
D4
D5
1
A0
A1
CURRENT DAC DATA
DO
D0
D1
D2
D3
D4
D5
PROG
PROG
RDY/BSY
DAC
OUTPUT
CURRENT
DAC VALUE
NON-VOLATILE
Doc. No. 25075-00 2/98 M-1
NEW
DAC VALUE
VOLATILE
DAC
OUTPUT
NEW
DAC VALUE
NON-VOLATILE
6
CURRENT
DAC VALUE
NON-VOLATILE
D6
D7
CAT514
this value is the same as that which had been there
previously no change in the DAC’s output is noticed.
Had the value held in the control register been different
from that stored in EEPROM then a change would occur
at the read cycle’s conclusion.
this feature, the new value must be reloaded into the
DAC control register prior to programming. This is because the CAT514’s internal control circuitry discards
the new data from the programming register two clock
cycles after receiving it (after reception is complete) if no
PROG signal is received.
TEMPORARILY CHANGE OUTPUT
Figure 3. Temporary Change in Output
The CAT514 allows temporary changes in DAC’s output
to be made without disturbing the settings retained in
EEPROM memory. This feature is particularly useful
when testing for a new output setting and allows for user
adjustment of preset or default values without losing the
original factory settings.
to
1
2
3
4
5
6
7
8
9
10
11
12
N
N+1 N+2
CS
NEW DAC DATA
DI
Figure 3 shows the control and data signals needed to
effect a temporary output change. DAC settings may be
changed as many times as required and can be made to
any of the four DACs in any order or sequence. The
temporary setting(s) remain in effect long as CS remains
high. When CS returns low all four DACs will return to the
output values stored in EEPROM memory.
1
A0
A1
D0
D1
D2
D3
D4
D5
D6
D7
D6
D7
CURRENT DAC DATA
D0
DO
D1
D2
D3
D4
D5
PROG
CURRENT
DAC VALUE
NON-VOLATILE
NEW
DAC VALUE
VOLATILE
CURRENT
DAC VALUE
NON-VOLATILE
DAC
OUTPUT
When it is desired to save a new setting acquired using
APPLICATION CIRCUITS
+5V
+5V
Ri
RF
+15V
+15V
VDD
CONTROL
& DATA
VREF H
–
CAT514
OPT
504
GND
+
VDD
VOUT
CONTROL
& DATA
OP 07
-15V
VREF L
VREF H
CAT514
OPT
504
GND
DAC INPUT
Ri
CAT514
OPT
504
GND
VREF L
VOUT
–
+
DAC OUTPUT
ANALOG
OUTPUT
CODE (V - V
VDAC = ———
FS ZERO ) + VZERO
255
RF
+15V
CONTROL
& DATA
-15V
Amplified DAC Output
+5V
VREF H
OP 07
RF
VOUT = (1 + –––) V DAC
RI
Buffered DAC Output
VDD
VOUT
+
VREF L
VOUT = VDAC
Vi
–
VFS = 0.99 VREF
VZERO = 0.01 VREF
VREF = 5V
R I = RF
MSB
LSB
1111
1111
255 (.98 V
——
REF ) + .01 VREF = .990 VREF
255
VOUT = +4.90V
1000
0000
V
= +0.02V
OUT
0111
1111
0000
0001
128 (.98 V
——
) + .01 V
= .502 V
REF
REF
REF
255
127
—— (.98 V
) + .01 V
= .498 V
255
REF
REF
REF
1 (.98 V
——
) + .01 V
= .014 V
255
REF
REF
REF
0000
0000
0 (.98 V
——
) + .01 V
= .010 V
REF
REF
REF
255
V
= -4.90V
OUT
OP 07
-15V
VOUT = VDAC ( R i+ RF) -Vi R F
Ri
For R i = RF
VOUT = 2VDAC -Vi
V
= -0.02V
OUT
V
= -4.86V
OUT
Bipolar DAC Output
7
Doc. No. 25075-00 2/98 M-1
CAT514
APPLICATION CIRCUITS (Cont.)
+5V
VREF
RC = —————
256 * 1 µA
+5V
VDD
VREF
VREFH
+VREF
VDD
Fine adjust gives ± 1 LSB change in V OFFSET
VREF
when VOFFSET = ———
2
VREFH
127RC
FINE ADJUST
DAC
+
(+VREF ) - (VOFFSET )
RC = ———————————
1 µA
127RC
FINE ADJUST
DAC
(-VREF ) + (VOFFSET+ )
Ro = ———————————
1 µA
+V
RC
COARSE ADJUST
DAC
V OFFSET
RC
COARSE ADJUST
DAC
+
GND
VREF L
+V
Ro
–
GND
VOFFSET
-VREF
VREF L
+
–
-V
Coarse-Fine Offset Control by Averaging DAC Outputs
for Single Power Supply Systems
Coarse-Fine Offset Control by Averaging DAC Outputs
for Dual Power Supply Systems
28 - 32V
V+
I > 2 mA
15K
10 µF
VDD
VREF H
1N5231B
VREF = 5.000V
VDD
VREF H
5.1V
10K
CONTROL
& DATA
CAT514
OPT
504
GND
CONTROL
& DATA
LT 1029
CAT514
OPT 504
GND
VREF L
VREF L
+
–
MPT3055EL
LM 324
OUTPUT
4.02 K
1.00K
Digitally Trimmed Voltage Reference
Doc. No. 25075-00 2/98 M-1
Digitally Controlled Voltage Reference
8
10 µF
35V
0 - 25V
@ 1A
CAT514
APPLICATION CIRCUITS (Cont.)
+5V
VREF
VIN
1.0 µF
LM 339
+
10K
–
VDD
+5V
VREF H
WINDOW 1
+
OPT 504
CAT514
VREF
–
VPP
WINDOW 1
DAC 1
+
10K
–
+5V
WINDOW 2
VOUT 1
+
CS
WINDOW 2
–
+
DAC 2
DI
VOUT 2
10K
–
+5V
WINDOW 3
WINDOW 3
+
DO
–
DAC 3
PROG
VOUT 3
+
WINDOW 4
10K
–
+5V
WINDOW 4
VOUT 4
+
CLK
–
DAC 4
WINDOW 5
+
GND
10K
–
+5V
WINDOW 5
+
VREF L
GND
WINDOW STRUCTURE
–
Staircase Window Comparator
+5V
VIN
VREF
1.0 µF
+
LM 339
10K
–
VDD
VREF H
CAT514
OPT
514
+5V
WINDOW 1
+
VREF
–
WINDOW 1
DAC 1
+
–
10K
+5V
WINDOW 2
VOUT 1
+
CS
DI
WINDOW 2
–
VOUT 2
+
DAC 2
10K
–
+5V
WINDOW 3
WINDOW 3
+
DO
PROG
–
DAC 3
VOUT 3
+
–
WINDOW 4
10K
+5V
WINDOW 4
VOUT 4
+
CLK
–
DAC 4
WINDOW 5
+
GND
10K
–
+5V
WINDOW 5
+
GND
VREF L
WINDOW STRUCTURE
–
Overlapping Window Comparator
9
Doc. No. 25075-00 2/98 M-1
CAT514
APPLICATION CIRCUITS (Cont.)
+5V
2.2K
VDD
VREF
4.7 µA
LM385-2.5
ISINK = 2 - 255 mA
+15V
DAC
+
+5V
CONTROL
& DATA
10K
OPT
504
CAT514
1 mA steps
2N7000
–
10K
39Ω1W
39Ω 1W
DAC
+
5 µA steps
2N7000
–
VREF L
GND
5 meg
5 meg
3.9K
10K
10K
–
TIP 30
+
-15V
Current Sink with 4 Decades of Resolution
+15V
51K
+
TIP 29
–
10K
10K
+5V
VDD
VREF H
5 meg
5 meg
39Ω 1W
DAC
39Ω 1W
CONTROL
& DATA
–
OPT 504
CAT514
5 meg
DAC
GND
BS170P
+
5 meg
1 mA steps
3.9K
–
VREF L
BS170P
5 µA steps
+
LM385-2.5
-15V
ISOURCE = 2 - 255 mA
Current Source with 4 Decades of Resolution
Doc. No. 25075-00 2/98 M-1
10
CAT514
ORDERING INFORMATION
Prefix
Device #
Suffix
CAT
514
J
Optional
Company ID
Product
Number
Package
P: PDIP
J: SOIC
I
-TE13
Tape & Reel
TE13: 2000/Reel
Temperature Range
Blank = Commercial (0˚C to +70˚C)
I = Industrial (-40˚C to +85˚C)
Notes:
(1) The device used in the above example is a CAT514JI-TE13 (SOIC, Industrial Temperature, Tape & Reel)
11
Doc. No. 25075-00 2/98 M-1