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Three New Op Amp Families
A/D and D/A Converters
DSPs and Mixed-Signal Processors
Channel Protectors, Temperature, Sw-Cap Inverter

Three New Op Amp Families

Single/Dual Rail­Rail

Single­supply OP162/OP262 325µV Vos, 15­MHz 650 µA Isy

The single OP162 and dual OP262 operational amplifiers combine low offset (325 µV max, 45 µV typical), wide bandwidth (15 MHz), and low power (650 µA max per amplifier­OP262 @ +25°C, +3­V supply). They will operate with single supplies from +2.7 to +12 V and are completely specified for operation at +3 V, + 5V and ±5 V.A quad version, OP462, is also available.

Their low offset is accompanied by low drift and noise (1µV/°C, 9.5nV/Hz at 1 kHz, (0.5 Vp­p from 0.1­10 Hz). Bias current is 600 nA max (360 typical), and current noise density at 1kHz is 0.4 pA/ Hz. The amplifiers are unity­gain stable, can slew at 10V/µs and settle to 0.1% of a 2­V step in <0.6 µs. They can be overdriven without suffering phase inversion.

Their outputs can swing rail­to­rail, i.e., to within 0.05 V max of either supply terminal with 250 µA load current, and to within 0.15 V max at 5 mA. Maximum output current is typically ±30 mA, and short­circuit current is ±80 mA.

Operating temperature range is ­40 to +125°C. The OP162G and OP262G are available in 8­pin plastic DIP and SOIC; the OP162H and OP262H are available in 8­pin TSSOPs.

Low­Power, High­Speed Amplifier

AD8005 draws only 400 mA of supply current, has
270­MHz bandwidth, 280 V/ms slew rate, 28­ns settling

The AD8005 is a current­feedback operational amplifier combining low power, high speed and fast settling­with good video specifications, and low distortion. It is especially useful as a power­conserving high­speed amplifier for signal conditioning in the signal chain, furnishing moderate drive current (10 mA). Typical applications include battery­powered portable equipment; loop­powered equipment­such as telecom line cards; and high­component­density systems requiring minimum dissipation.

It is specified for operation on ±5­volt dual and +5­volt single supplies, drawing typically 400 µA of quiescent current (560 µA worst case, over temperature­ ­40 to +85°C­with ±5­V supplies). It has a bandwidth of 270 MHz at gain of +1, and 170 MHz at +2, with 280 V/µs slew rate and 28­ns settling time to 0.1% (2­V step). For video applications, its differential gain and phase errors are 0.11% and 0.4°, and its gain is flat within 0.1 dB to 30 MHz.

Distortion is ­63 dBc at 1 MHz and ­50 dBc at 10 MHz; and noise at 10 MHz is only 4 nV/√Hz. The AD8005 is currently available in DIP and SO­8­and will shortly be available in 5­pin SOT23. Price in 1000s is $1.45. Faxcode* 2053 or Circle 9.

Gain­of­2 Buffer Amplifier: 260­MHz BW

Dual AD8079 is available with gains +2.0 and +2.2 for video buffering:
50­MHz flatness; 0.01% G, 0.02°

The AD8079 is a dual fixed­gain buffer amplifier with principal applications in video systems­for example, differential and single­ended line driving. It is ideal for driving and unloading video crosspoint switches, such as the 16 x 16 AD8116. It is available in two versions (A, B) with gains of +2.0, +2.2. The internal gain­setting resistors and optimized pinout effectively isolate the inverting input from parasitic capacitance, resulting in excellent gain flatness. The B­version’s +2.2 gain is useful in compensating for gain losses elsewhere in a system.

It has a ­ 3­dB bandwidth of 260 MHz, with 0.1­dB flatness to 50 MHz; excellent differential gain and phase performance (0.01%, 0.02°); low power drain (50 mW, or 5 mA, per amplifier—5.75 mA max); 0.1% gain matching and low crosstalk (­ 70 dB at 5 MHz); and its high output (70 mA) can drive up to 4 video loads per amplifier. Its slew rate and settling time to 0.1% are 750 V/µs and 40 ns, respectively, for a 2­V output step. Distortion is low, at ­ 65 dBc THD for a 5 MHz signal.

Using ±5­volt supplies, it operates from ­ 40 to +85°C and is available in a small 8­lead plastic SOIC package. Both versions are priced at $3.50 in 1000s. Faxcode* 2072

A/D and D/A Converters

Ultrafast & Fast 14­ bit A/D Converters

3­ MSPS AD9243 works on +5 V supply, uses 110 mW
330­ kSPS serial­ output AD7851 uses +5 V, 60 mW

The AD9243 and AD7851 are two of the fastest 14­ bit monolithic A/D converters available today. They are smaller, less costly, and run much cooler than hybrid devices of comparable speed and resolution.

With its 3­ MSPS sampling rate and 40­ MHz full­ power signal bandwidth, the AD9243 creates a new IC speed class, especially useful in communications and imaging, but of interest in many other fields. Its low dissipation, single 5­ V supply, differential inputs, and internal reference, as well as its low price and small package, make possible new applications, as well as providing an ideal upgrade for 12­ bit devices.

Besides its 333­ ksps sampling rate, 20­ MHz full­ power signal bandwidth, and serial interface, the AD7851 has a number of useful features. For example, its already low maximum dissipation of <90 mW can be further reduced to 52.5 µW max in sleep mode; with the external clock on, dissipation in that mode is increased to only 105 µW. The device contains self­ and system­ calibration options to ensure accurate operation over time and temperature. It powers up with a set of default conditions, and can be operated as a read­ only ADC.

Both devices are available for ­40 to +85° C operation. The AD7851 has a choice of 24­ pin DIP and SOIC, as well as SSOP, packages.

AD9243 AD7851A AD7851K
Throughput (MSPS) 3.0 0.333 0.285
SNR, dB min* 77 77 78
SINAD, dB min* 76 77 78
SFDR, dB* 91 typ 87 max 87 max
SFDR, dB, AIN @ Nyquist 84 typ 84 max 84 max
THD, dB max* ­80 ­86 ­86
IDD, mA max (5 V ± 5%) 29 17 17
TMIN/TMAX (° C) C­40/+85 ­40/+85 ­40/+85
Smallest Package MQFP­ 44 SSOP­ 24 SSOP­ 24

Faxcode 2036 1873 1873
Price (1000s) $49 $12.50 $14.75
*AIN: AD9243, 500 kHz; AD7851, 10 kHz

Low­ Power DACs need only 100 mA

12/10­ bit AD7390/7391 are specified for +3 V & +5 V
Serial input, 1.1­ mm­ high TSSOP­ 8 package,

The AD7390 and AD7391 are pin­ compatible 12­ and 10­ bit multiplying D/A converters available in the ultra­ thin TSSOP­ 8 package (just 1.1 mm high). Power consumption is 100 µA max with 3­ or 5­ volt supply (165 µW typical at 3 V), and output is rail­ to­ rail. Pin compatibility means that the user can trade off resolution and cost without changing the physical layout. The external reference can be any value from 0 to VDD.

Typical applications are in setting dc voltage set points in digitally controlled calibration and adjustment, for communications, portable instruments, process control, and automotive applications. The TSSOP­ 8 package is ideal for use in PCMCIA cards.

A double­ buffered serial­ data interface offers high speed, 3­ wire, SPI, and microcontroller­ compatible inputs using data­ in, clock, and load­ strobe pins. In addition, a CLR input sets the output to zero scale at power­ on or on user demand.

The AD7390 and AD7391 are specified over the ­40 to +85/125°C range, and they are available in plastic DIP and SO­ 8, as well as TSSOP­ 8 packages. Prices in 1000s start at $2.80 (10 bits, PDIP & SOIC). Faxcode* 1957

60­ MSPS Dual ADC

8­ bit AD9059 works on +5 V, TTL/CMOS +3 V or +5­V logic

The AD9059 has two 8­ bit sampling A/D converters on a single monolithic chip. Powered from a single 5­ V supply, it is a complete solution, including two track­ holds and an internal +2.5­ V reference. It provides excellent dynamic performance for conversion rates <= 60 MHz, with low dissipation (400 mW), wide analog band­ width (120 MHz), and 44.5­ dB typical SINAD (7.2 ENOB) with 10.3­ MHz input. It will operate with +5­ or +3­ V logic (a separate supply pin powers the digital outputs).

Besides any multi­ ADC application, the AD9059 is well­ suited to I&Q digital communications (QAM demodulation) in wireless receivers and cable modems. It operates over the full ­ 40 to +85° C temperature range and is housed in a tiny 28­ lead SSOP package. Its price (1000s) is $11.88, and $195 for an evaluation board. Faxcode* 1937

14-Bit Quad DAC

AD7836’s DACs can be individually referenced

The AD7836 contains four 14-bit DACs with ±10-V output (suitable for automatic test equipment), with separate plus and minus reference inputs for each DAC. An override register permits the device to output a user-defined level at any time without affecting the contents of the DAC registers. The ground reference terminal for each DAC is available for applying an external offset voltage. The DACs are 14-bit monotonic over temperature (­40 to +85°C), with 12-bit integral linearity.

Typical applications are wherever multiple DACs with high resolution are needed. Examples include level-setting for pin electronics in ATE, and industrial process control and instrumentation. The AD7836AS is housed in a 44-pin PQFP and requires ±15-V supplies and a 5-V logic supply. Price in 1000s is $22.35. Faxcode* 2030

DSPs and Mixed-Signal Processors

Plug-and-Play Audio

AD1815/16 Controllers Support popular applications

The AD1815 SoundComm™ and AD1816 SoundPort™ Controllers are single-chip ISA Plug-and-Play audio subsystems for adding 16-bit stereo support to personal computers. They provide an integrated solution for Windows 95, Windows NT, OS/2, and DOS-based systems, delivering CD-quality fidelity and 5 channels of digital mixing. The AD1815 includes V.34-class modem I/O capabilities for the cost of a SoundBlaster®-only game audio IC. The AD1816’s 3-D Phat stereo enhancement circuitry expands the sound field of typical PC speakers, for increased user immersion.

They add audio capabilities to both mother-boards and add-in cards. The AD1815’s V.34-capable modem front end (ADC & DAC) can be used for host-based telephony functions, e.g., fax, modem, and speaker-phones. The AD1816 can decode other devices for use in multi-function add-in cards.

Features include software and hardware volume controls, an MPC level-2/3 mixer, an integrated FM compatible music synthesizer­plus an MPU-401-compatible MIDI port, an integrated enhanced digital game port, two I2S digital audio serial port inputs, and a bidirectional DSP serial port; they support dual type F FIFO DMA.

Running on a 33-MHz clock, they have full-duplex capture and playback operation at different sample rates, can support up to six different sample rates simultaneously, and provide programmable sample rates from 4 kHz to 55.2 kHz, with 1-Hz resolution. They employ continuous-time oversampling for low-latency mixing, sample-rate con-version, and signal-stream synchronization of multiple audio, communications, and video signals having disparate sample rates.

The AD1815 and AD1816 have built-in 24-mA bus drivers.They operate from 5-volt supplies. A power-down mode is available. They are housed in 100-pin PQFP and TQFP packages. Prices of the AD1815JS/AD1816JS are $17.50/$18.50 (1000s).

16-Bit Fixed-Point DSPs Trim Cost, Space

ADSP-2185 and ADSP-2186 have 32/16K on-chip RAM 3.3-volt versions available for these and ADSP-2181

Two new members of the ADSP-218x line of embedded-SRAM fixed-point DSPs (Analog Dialogue 28-3, p. 12) add ultra-low cost and small size to the family's long list of key benefits for designers. The new additions are the ADSP-2185, with 32 K words of built-in SRAM, and the ADSP-2186, with 16 K words of SRAM.

Squeezed into compact 100-pin thin quad flatpacks (TQFP), these new members conserve circuit board area, making them suitable for applications in tight spaces or requiring multiple processors. Typical applications that can benefit from the smaller processors are modem functions for Internet service providers and voice compression at central-office switch networks.

Besides their small size, they are available in a choice of 5-volt or 3.3-volt “L” (for low-power) versions (an ADSP-2181 version is also available for 3.3 V—ADSP-2183). The ADSP-2185 and ADSP-2186 also sport considerably lower prices: $17.10 and $9.90 in very large quantity.

Like other ADSP-218x products, these devices have a great many input/output (I/O) and direct memory access (DMA) features that speed data throughput without burdening the processing core. The designer has choices: a 16-bit internal DMA port that gives a host processor access to the DSP's on-chip memory; a byte DMA port that can access instructions and data stored in low-cost external EPROMs; and a pair of on-chip serial ports that connect directly to high-speed telecommunications networks.

To fit into smaller packages, yet still offer the full range of memory access features, both chips multiplex some serial-port, programmable-flag, interrupt, and external bus functions.

The new DSPs are pin-compatible; that is, designers can interchange them to fit the price/performance goals of a particular end use. What's more, both can execute code written for ADI's ADSP-2100 fixed-point DSP family, the industry's largest family of code-compatible DSPs.

Supply On-Chip RAM
Processor Voltage PM DM Package
ADSP-2181 5 16 K 16 K 128-PQFP, TQFP
ADSP-2183 3.3 16 K 16 K 128-PQFP, TQFP
ADSP-2185 5 16 K 16 K 100-TQFP
ADSP-2185L 3.3 16 K 16 K 100-TQFP
ADSP-2186 5 8 K 8 K 100-TQFP
ADSP-2186L 3.3 8 K 8 K 100-TQFP

Mixed Bag: Channel Protectors, Temperature, Sw-Cap Inverter

Multiple Channel Protectors

Three-channel ADG466, 8-channel ADG467 Provide overvoltage and fault protection

The ADG466 and ADG467 are monolithic ICs containing 3- and 8-channel protectors. When connected in series with the signal path, they will protect sensitive components from steady-state or transient overvoltage and fault conditions of up to ±40 V.

Each channel protector consists of three MOSFETs in series—an n-channel, a p-channel, and an n-channel (separated by a dielectric trench to prevent latchup). In normal operation, with signals from 0.8 V below VDD to 1.2 V above VSS, the channel protector behaves like a series resistor (typically 60 ohms), with leakage of about 1 nA. But when the applied voltage goes above VDD or below VSS—even with 0 supply voltage (power off)—one of the MOSFETs will switch off, opening the input circuit and clamping the output.

Because the channel protection works whether the supplies are present or not, and no control logic is required, these devices are ideal for use in applications where correct power sequencing cannot always be guaranteed (for example, hot-insertion rack systems).

Operating temperature range is ­40 to +85°C. The ADG466 is available in 8-pin DIP, SOIC, and µSOIC; the ADG467 is available in 18-pin SOIC and 20-pin SSOP. ADG466/467 prices (1000) are $1.25/$2.15. Faxcode* 2067

Regulated Switched-Cap V Converter

ADP3603 provides ­ 3.0 V, up to 50 mA, 3% accuracySwitches at 120 kHz; no inductors, small capacitors

The ADP3603 is a high-accuracy switched-capacitor voltage converter operating at a 120-kHz switching frequency, generated by an internal 240-kHz clock. It accepts +5-V dc input and furnishes up to 50 mA at a regulated ­ 3.0 V (±3%). The ADP3603 is a lower-power (and -cost) version of the 120-mA ADP3604, described in Analog Dialogue 30-3 (p. 19, also p. 14, this issue).

The ADP3603 is primarily designed for use as a negative-voltage regulator/inverter, allowing a single battery or system supply to suffice in applications calling for its positive voltage to be supplemented locally with negative voltage.

The operating principle is simple: a “pump” capacitor is switched between the input circuit and the output circuit, transferring increments of charge from an input storage capacitor to the output storage capacitor. Voltage inversion is achieved by reversing the switch connections to the output capacitor. No inductors are necessary.

Typical areas of application include general-purpose voltage inversion and regulation, computer peripherals and add-on cards, portable instruments, battery-powered devices, pagers and radio control receivers, disk drives, and mobile phones.

The AD3603 is housed in an 8-pin SO package and operates from ­40 to +85°C. An evaluation board is available. AD3603 is priced at $1.70 in 1000s. Faxcode* 1982

Temperature Sensor

2-terminal TMP17 in SO-8 1 mA/K PTAT output current

The TMP17 is a monolithic temperature-to-current transducer that provides an output current proportional to absolute temperature (PTAT), 1 microampere per kelvin, for temperatures from ­40 to +105°C (233 to 378 K). Current is independent of applied voltage, for supplies from +4 to +30 V.

The device is inherently linear (within 0.5°C) and stable (repeatability and long-term stability within 0.2°C), and initial calibration error (25°C) is ±2.5°C max (F grade). Initial calibration error can be trimmed out by adjusting the measuring resistance that converts current to voltage.

Because the TMP17 is a current source, its output is immune to voltage noise pickup and IR drops in the signal leads in remote applications. The TMP17’ s small size, low cost, stability, and simplicity make it useful in applications such as cold-junction compensation, thermal compensation of instrumentation, and over-temperature warning systems in automotive, HVAC, and industrial temperature control.

The TMP17 is housed in a tiny SO-8 package and available in F and G grades. Prices in 1000s are $2.28 and $1.52. Faxcode* 2040

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