CAT523
Configured Digitally Programmable Potentiometer (DPP™): Programmable Voltage Applications
FEATURES
s Two 8-bit DPPs configured as programmable
H
GEN FR ALO
EE
APPLICATIONS
s Automated product calibration.
LE
A D F R E ETM
voltage sources in DAC-like applications
s Common reference inputs s Non-volatile NVRAM memory wiper storage s Output voltage range includes both supply rails s 2 independently addressable buffered
s Remote control adjustment of equipment s Offset, gain and zero adjustments in self-
calibrating and adaptive control systems.
s Tamper-proof calibrations. s DAC (with memory) substitute
output wipers
s 1 LSB accuracy, high resolution s Serial microwire-like interface s Single supply operation: 2.7V - 5.5V s Setting read-back without effecting outputs
DESCRIPTION The CAT523 is a dual, 8-bit digitally-programmable potentiometer (DPP™) configured for programmable voltage and DAC-like applications. 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. The two independently programmable DPPs have a common output voltage range which includes both supply rails. The wipers are buffered by rail to rail op amps. Wiper settings, stored in non-volatile NVRAM memory, are not lost when the device is powered down and are automatically reinstated when power is returned. Each wiper can be dithered to test new output FUNCTIONAL DIAGRAM
RDY/BSY V DD
values without effecting the stored settings and stored settings can be read back without disturbing the DPP’s output. Control of the CAT523 is accomplished with a simple 3wire, Microwire-like serial interface. A Chip Select pin allows several CAT523's to share a common serial interface and communication back to the host controller is via a single serial data line thanks to the CAT523’s TriStated Data Output pin. A RDY/BSY output working in concert with an internal low voltage detector signals proper operation of non-volatile NVRAM memory Erase/ Write cycle. The CAT523 is available in the 0°C to 70°C Commercial and -40°C to + 85°C Industrial operating temperature ranges and offered in 14-pin plastic DIP and SOIC mount packages. PIN CONFIGURATION
VREFH
14
3
1
DIP Package (P, L)
VDD CLK RDY/BSY 1 2 3 14 13 VREFH VOUT1 VOUT2 NC
NC VREFL
SOIC Package (J, W)
VDD CLK RDY/BSY CS DI DO PROG 1 2 3 14 13 VREFH VOUT1 VOUT2
NC NC VREFL
PROG
7
PROGRAM CONTROL
DI
5 WIPER CONTROL REGISTER AND NVRAM
CS
+
13 V OUT1
CLK
2
SERIAL CONTROL
DI DO PROG
12 CAT 4 11 523 5 10 6 9 7 8
12 4 CAT 11 523 5 10 6 9 7 8
GND
GND
CS
4
+
12
V OUT2
SERIAL DATA OUTPUT REGISTER
6 DO
CAT523
8
GND
9
V REFL
© 2004 by Catalyst Semiconductor, Inc. Characteristics subject to change without notice
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CAT523
ABSOLUTE MAXIMUM RATINGS Supply Voltage* VDD to GND Inputs CLK to GND CS to GND DI to GND RDY/BSY to GND PROG to GND VREFH to GND VREFL to GND Outputs D0 to GND VOUT 1– 4 to GND -0.5V to +7V -0.5V to VDD +0.5V -0.5V to VDD +0.5V -0.5V to VDD +0.5V -0.5V to VDD +0.5V -0.5V to VDD +0.5V -0.5V to VDD +0.5V -0.5V to VDD +0.5V -0.5V to VDD +0.5V -0.5V to VDD +0.5V Operating Ambient Temperature Commercial (‘C’ or Blank suffix) 0°C to +70°C Industrial (‘I’ suffix) -40°C to +85°C Junction Temperature +150°C Storage Temperature -65°C to +150°C Lead Soldering (10 sec max) +300°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
VZAP(1) ILTH(1)(2)
Parameter
ESD Susceptibility Latch-Up
Min
2000 100
Max
Units
Volts mA
Test Method
MIL-STD-883, Test Method 3015 JEDEC Standard 17
NOTES: 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.
POWER SUPPLY Symbol Parameter IDD1 IDD2 Supply Current (Read) Supply Current (Write) Conditions Normal Operating Programming, VDD = 5V VDD = 3V VDD Operating Voltage Range Min — — — 2.7 Typ 400 1600 1000 — Max 600 2500 1600 5.5 Units µA µA µA V
LOGIC INPUTS Symbol IIH IIL VIH VIL Parameter Input Leakage Current Input Leakage Current High Level Input Voltage Low Level Input Voltage Conditions VIN = VDD VIN = 0V Min — — 2 0 Typ — — — — Max 10 -10 VDD 0.8 Units µA µA V V
LOGIC OUTPUTS Symbol Parameter VOH VIL High Level Output Voltage Low Level Output Voltage Conditions IOH = -40µA IOL = 1 mA, VDD = +5V IOL = 0.4 mA, VDD = +3V Min VDD -0.3 — — Typ — — — Max — 0.4 0.4 Units V V V
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CAT523
POTENTIOMETER CHARACTERISTICS VDD = +2.7V to +5.5V, VREFH = VDD, VREFL = 0V, unless otherwise specified Symbol RPOT Parameter Potentiometer Resistance RPOT to RPOT Match Pot Resistance Tolerance Voltage on VREFH pin Voltage on VREFL pin Resolution INL DNL ROUT IOUT TCRPOT CH/CL Integral Linearity Error Differential Linearity Error Buffer Output Resistance Buffer Output Current TC of Pot Resistance Potentiometer Capacitances 300 8/8 2.7 0V 0.4 0.5 0.25 1 0.5 10 3 Conditions See Note 3 — Min Typ 24 +0.5 +1 +20 VDD VDD - 2.7 Max Units kΩ % % V V % LSB LSB Ω mA ppm/˚C pF
AC ELECTRICAL CHARACTERISTICS: VDD = +2.7V to +5.5V, VREFH = VDD, VREFL = 0V, unless otherwise specified Symbol Digital
tCSMIN tCSS tCSH tDIS tDIH tDO1 tDO0 tHZ tLZ tBUSY tPS tPROG 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 Output Delay to Low-Z Erase/Write Cycle Time PROG Setup Time Minimum Pulse Width Minimum CLK High Time Minimum CLK Low Time Clock Frequency DPP Settling Time to 1 LSB 150 100 0 50 50 — — — — — 150 700 500 300 DC — — — — — — — — — 400 400 4 — — — — — 3 6 — — — — — 150 150 — — 5 — — — — 1 10 10 ns ns ns ns ns ns ns ns ns ms ns ns ns ns MHz µs µs
Parameter
Conditions
Min
Typ
Max
Units
CL=100pF, see note 1
Analog
tDS CLOAD = 10 pF, VDD = +5V CLOAD = 10 pF, VDD = +3V
NOTES: 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. The 24kΩ +20% resistors are configured as 4 resistors in parallel which would provide a measured value between VREFH and VREFL of 6kΩ +20%. The individual 24kΩ resistors are not measurable but guaranteed by design and verification of the 6kΩ +20% value.
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CAT523
A. C. TIMING DIAGRAM
to
1
2
3
4
5
t CLK H CLK
t CSS CS
t CLK L
t CSH
t CSMIN
t DIS DI t DIH
t LZ DO
t DO0
t HZ t DO1
PROG t PS t PROG RDY/BSY t
BUSY
to
1
2
3
4
5
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CAT523
PIN DESCRIPTION Pin
1 2 3 4 5 6 7 8 9 10 11 12 13 14
DPP 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 DPP output voltage. No Connect. No Connect. DPP output channel 2. DPP output channel 1. Maximum DPP output voltage.
Name
VDD CLK RDY/BSY CS DI DO PROG GND VREFL NC NC VOUT2 VOUT1 VREFH
DPP OUTPUT VOUT1 VOUT2
A0 0 1
A1 0 0
DEVICE OPERATION The CAT523 is a dual 8-bit configured digitally programmable potentiometer (DPP) whose outputs can be programmed to any one of 256 individual voltage steps. Once programmed, these output settings are retained in non-volatile memory and will not be lost when power is removed from the chip. Upon power up the DPPs return to the settings stored in non-volatile memory. Each DPP 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. DIGITAL INTERFACE The CAT523 employs a 3 wire, Microwire-like, 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 DPP 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. 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. CHIP SELECT Chip Select (CS) enables and disables the CAT523’s
read and write operations. When CS is high data may be read to or from the chip, and the Data Output (DO) pin is active. Data loaded into the DPP control registers will remain in effect until CS goes low. Bringing CS to a logic low returns all DPP outputs to the settings stored in nonvolatile memory and switches DO to its high impedance Tri-State mode. 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 CAT523’s clock controls both data flow in and out of the IC and non-volatile 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 non-volatile memory, even though the data being saved may already be resident in the DPP wiper control register. No clock is necessary upon system power-up. The CAT523’s internal power-on reset circuitry loads data from non-volatile memory to the DPPs without using the external clock. 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.
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CAT523
VREF VREF, the voltage applied between pins VREFH andVREFL, sets the DPP’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. READY/BUSY When saving data to non-volatile memory, the Ready/ Busy output (RDY/BSY) signals the start and duration of the non-volatile 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 CAT523 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 non-volatile programming, RDY/BSY will remain high following the program command indicating a failure to record the desired data in non-volatile memory. DATA OUTPUT Data is output serially by the CAT523, 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 523s to share a single serial data line and simplifies interfacing multiple 523s to a microprocessor. WRITING TO MEMORY Programming the CAT523’s non-volatile memory is accomplished through the control signals: Chip Select (CS) and Program (PROG). With CS high, a start bit followed by a two bit DPP address and eight data bits are clocked into the DPP control register via the DI pin. Data enters on the clock’s rising edge. The DPP output changes to its new setting on the clock cycle following D7, the last data bit. 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 non-volatile memory cells. The CAT523’s non-volatile memory cells will endure over 100,000 write cycles and will retain data for a minimum of 100 years without being refreshed. READING DATA Each time data is transferred into a DPP wiper 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 DPP’s output. This feature allows µPs to poll DPPs for their current setting without disturbing the output voltage but it assumes that the setting being read is also stored in non-volatile memory 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 non-volatile memory setting is reloaded into the DPP wiper control register.
Figure 1. Writing to Memory
Figure 2. Reading from Memory
to 1 2 3 4 5 6 7 8 9 10 11 12
CS
NEW DPP DATA
DI
CURRENT DPP DATA
1
A0
A1 CURRENT DPP DATA
DO
D0
D1
D2
D3
D4
D5
D6
D7
PROG
RDY/BSY
DPP OUTPUT
DPP OUTPUT
DPP VALUE DPP VALUE DPP VALUE
CURRENT DPP VALUE
NON-VOLATILE
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CAT523
Since this value is the same as that which had been there previously no change in the DPP’s output is noticed. Had the value held in the control register been different from that stored in non-volatile memory then a change would occur at the read cycle’s conclusion. TEMPORARILY CHANGE OUTPUT The CAT523 allows temporary changes in DPP’s output to be made without disturbing the settings retained in non-volatile 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. Figure 3 shows the control and data signals needed to effect a temporary output change. DPP wiper settings may be changed as many times as required and can be made to any of the two DPPs in any order or sequence. The temporary setting(s) remain in effect long as CS remains high. When CS returns low all two DPPs will return to the output values stored in non-volatile memory. When it is desired to save a new setting acquired using this feature, the new value must be reloaded into the DPP wiper control register prior to programming. This is because the CAT523’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. Figure 3. Temporary Change in Output
to 1 2 3 4 5 6 7 8 9 10 11 12 N N+1 N+2
CS
NEW DPP DATA 1 A0 A1 D0 D1 D2 D3 D4 D5 D6 D7
DI
CURRENT DPP DATA DO D0 D1 D2 D3 D4 D5 D6 D7
PROG
DPP OUTPUT
CURRENT DPP VALUE NON-VOLATILE
NEW DPP VALUE VOLATILE
CURRENT DPP VALUE NON-VOLATILE
APPLICATION CIRCUITS
DPP INPUT DPP OUTPUT CODE VDPP = ——— (VFS - VZERO ) + V ZERO 255 VFS = 0.99 VREF VZERO = 0.01 V REF 255 —— (.98 VREF) + .01 VREF = .990 VREF 255 128 —— (.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 —0 (.98 V — ) + .01 V = .010 V REF REF REF 255 VREF = 5V R I = RF V OUT= +4.90V
CONTROL & DATA VDD
ANALOG OUTPUT
+5V Vi Ri +15V VREFH RF
MSB
LSB
1111 1111
– + OP 07
VOUT
CAT523
GND VREFL
1000 0000 0111 1111 0000 0001
V V V
OUT OUT OUT
= +0.02V = -0.02V = -4.86V
-15V
VOUT = V DPP ( R i+ RF) -Vi R F Ri For R i = RF VOUT = 2VDPP -Vi
0000 0000
V
OUT
= -4.90V
Bipolar DPP Output
+5V Ri +15V VDD CONTROL & DATA VREFH RF
– + OP 07
VOUT
CAT523
GND VREFL
-15V
RF VOUT = (1 + –––) V DPP RI
Amplified DPP Output
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CAT523
APPLICATION CIRCUITS (Cont.)
+5V +VREF VREFH
VREF RC = ————— 256 * 1 µA +5V VREF VREFH Fine adjust gives ± 1 LSB change in V OFFSET VREF when V OFFSET = ——— 2 127RC
VDD
VDD
FINE ADJUST DPP
127RC + (+VREF ) - (VOFFSET ) RC = ——————————— 1 µA (-VREF ) + (VOFFSET+ ) Ro = ——————————— 1 µA
FINE ADJUST DPP
COARSE ADJUST DPP
RC
+V COARSE ADJUST DPP RC V OFFSET
GND VREFL Ro -VREF VOFFSET
+ –
+V
+ –
-V
GND
VREFL
Coarse-Fine Offset Control by Averaging DPP Outputs for Single Power Supply Systems
Coarse-Fine Offset Control by Averaging DPP Outputs for Dual Power Supply Systems
28 - 32V
V+
I > 2 mA
15K 10 µF
1N5231B
VDD CONTROL & DATA
VREFH
VREF = 5.000V
VDD VREFH 5.1V 10K
CAT523
GND VREFL
LT 1029
CONTROL & DATA
CAT523
GND VREFL
+ – LM 324
MPT3055EL
OUTPUT 4.02 K 1.00K 10 µF 35V 0 - 25V @ 1A
Digitally Trimmed Voltage Reference
Digitally Controlled Voltage Reference
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CAT523
APPLICATION CIRCUITS (Cont.)
+5V 2.2K VDD VREFH 4.7 µA
LM385-2.5
+15V
ISINK = 2 - 255 mA
DPP
+5V 10K
+ –
10K
2N7000
39Ω1W 39Ω 1W
1 mA steps
CONTROL & DATA
CAT523
DPP
+ 2N7000 –
5 µA steps
GND
VREFL
5 meg
5 meg
3.9K
10K
10K
– + TIP 30
-15V
Current Sink with 4 Decades of Resolution
+15V
51K
+ TIP 29 –
10K +5V 10K
VDD
VREFH
5 meg
5 meg
39 Ω 1W 39 Ω 1W
DPP
CONTROL & DATA
CAT523
5 meg
– +
5 meg
BS170P
1 mA steps
3.9K
DPP
GND
VREFL
– BS170P + LM385-2.5
5 µA steps
-15V
ISOURCE = 2 - 255 mA
Current Source with 4 Decades of Resolution
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CAT523
ORDERING INFORMATION
Prefix CAT Device # 523 Suffix J I -TE13
Optional Company ID
Product Number
Package P: PDIP J: SOIC L: PDIP (Lead free, Halogen free) W: SOIC (Lead free, Halogen free)
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 CAT523JI-TE13 (SOIC, Industrial Temperature, Tape & Reel)
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CAT523
REVISION HISTORY
Date 3/16/2004 7/12/2004 Rev. D E Reason Updated Potentiometer Characteristics Updated Functional Diagram Updated Potentiometer Characteristics Added Note 3 to Potentiometer/AC Characteristics tables
Copyrights, Trademarks and Patents Trademarks and registered trademarks of Catalyst Semiconductor include each of the following:
DPP ™ AE2 ™
Catalyst Semiconductor has been issued U.S. and foreign patents and has patent applications pending that protect its products. For a complete list of patents issued to Catalyst Semiconductor contact the Company’s corporate office at 408.542.1000.
CATALYST SEMICONDUCTOR MAKES NO WARRANTY, REPRESENTATION OR GUARANTEE, EXPRESS OR IMPLIED, REGARDING THE SUITABILITY OF ITS PRODUCTS FOR ANY PARTICULAR PURPOSE, NOR THAT THE USE OF ITS PRODUCTS WILL NOT INFRINGE ITS INTELLECTUAL PROPERTY RIGHTS OR THE RIGHTS OF THIRD PARTIES WITH RESPECT TO ANY PARTICULAR USE OR APPLICATION AND SPECIFICALLY DISCLAIMS ANY AND ALL LIABILITY ARISING OUT OF ANY SUCH USE OR APPLICATION, INCLUDING BUT NOT LIMITED TO, CONSEQUENTIAL OR INCIDENTAL DAMAGES.
Catalyst Semiconductor products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the Catalyst Semiconductor product could create a situation where personal injury or death may occur. Catalyst Semiconductor reserves the right to make changes to or discontinue any product or service described herein without notice. Products with data sheets labeled "Advance Information" or "Preliminary" and other products described herein may not be in production or offered for sale. Catalyst Semiconductor advises customers to obtain the current version of the relevant product information before placing orders. Circuit diagrams illustrate typical semiconductor applications and may not be complete.
Catalyst Semiconductor, Inc. Corporate Headquarters 1250 Borregas Avenue Sunnyvale, CA 94089 Phone: 408.542.1000 Fax: 408.542.1200 www.catsemi.com
Publication #: Revison: Issue date: Type:
2005 E 7/12/04 Final
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