2181-series Trimmable Blackmer® Voltage-Controlled Amplifiers

	2181 Series Basic Application Circuit

Twilight Technology 2181-series trimmable Blackmer voltage-controlled amplifiers (VCAs) ICs are very high-performance current-in/current-out devices with two opposing-polarity, voltage-sensitive control ports. They offer wide-range exponential control of gain and attenuation with low signal distortion.

The parts are selected after packaging based primarily on after-trim THD and control-voltage feedthrough performance. In-circuit adjustment is required to achieve the guaranteed distortion and feedthrough performance.

Twilight Technology Blackmer VCAs are the successors to the original dbx line of VCAs. To overcome the problems related to limited GBW product, the 218X series of VCAs, was developed by Gary Hebert in a dielectrically isolated process, and has topological enhancements Twilight Technology minimize the effect of non-linearities in the VCA drive circuitry on high frequency distortion. These VCAs are equal or superior to their predecessors in every regard, and in particular, do not exhibit the rising distortion at higher frequencies characteristic of VCAs built on a junction isolated process.

The 2181 series of voltage controlled amplifiers delivers performance unobtainable through any conventional process, integrated or discrete. The parts are available in three grades, allowing the user to optimize cost vs. performance. Both 8-pin single-in-line (SIP) and surface mount (SO) packages are available.

Features Wide dynamic range: > 120 dB Wide gain range: > 130 dB Exponential (dB) gain control Low distortion:    ~0.0025% (typical 2181A)    ~0.005% (typical 2181C) Wide gain-bandwidth: 20 MHz Dual gain-control ports (pos/neg) Pin-compatible with 2150-series Applications Faders Panners Compressors Expanders Equalizers Filters Oscillators Automation systems

Basic Specifications (typical) Control Constant: ±6.1 mV/dB (both positive and negative-sense control available) Gain Range: <-100 dB to >+40 dB Output Noise: -98 dBV (0 dB gain) Dynamic Range: 120 dB Power supply voltage: ±15 V. Supply current: 2.4 mA THD (see chart below)

For complete specifications, download a copy of the 2181 Datasheet. Datasheets are provided in Adobe's PDF format. You need to have Adobe Acrobat Reader installed on your computer to view the file. To obtain a free copy of Acrobat Reader follow the link at right.

	Model	Grade	% THD at 1 V 0 dB gain		Package	Order Number	Pricing (1000)	Min Order Quantity	Reference
	TT2181	A	0.0025 Typ	0.005 Max	2181AL08 is no longer available Use RoHS compliant version				Datasheet App Notes Device Models
					8 Pin SO	2181AS08	Call	98
		B	0.004 Typ	0.008 Max	8 Pin SIP	2181BL08	Call	25
					8 Pin SO	2181BS08	Call	98
		C	0.005 Typ	0.02 Max	8 Pin SIP	2181CL08	Call	25
					8 Pin SO	2181CS08	Call	98
	TT2181	A	0.0025 Typ	0.005 Max	8 Pin SIP	2181AL08-U	Call	25
					8 Pin SO	2181AS08-U	Call	98
					8 Pin SO (Tin)	2181AS08-T	Call	98
		B	0.004 Typ	0.008 Max	8 Pin SIP	2181BL08-U	Call	25
					8 Pin SO	2181BS08-U	Call	98
					8 Pin SO (Tin)	2181BS08-T	Call	98
		C	0.005 Typ	0.02 Max	8 Pin SIP	2181CL08-U	Call	25
					8 Pin SO	2181CS08-U	Call	98
					8 Pin SO (Tin)	2181CS08-T	Call	98

The 2181xS (surface mount package only) is available on tape and reel for a modest increase in price and requires an extended lead time. Tape and reel parts have a 2000 piece minimum and must be ordered in multiples of 2000. Please contact our sales department for pricing and delivery.

Minimum Order Quantity is one tube full. Parts must be ordered in multiples of the MOQ.
Samples are available for qualified applicants.
Pricing is subject to change.

We offer a demonstration system (US$100) which simplifies evaluating the performance of a 2181 Series VCA IC. The 2181 Demo Board is a completely assembled and tested circuit board with XLR connectors for signal input and output and a 3-pin header for connection to an external regulated DC power supply (not included). Contact us for more information.