This product is currently being phased out of production.
Not recommended for new designs.

For assistance in finding alternate products, please use the selection table below.

The AD1991 is a two-channel BTL or four-channel single-ended class-D audio power output stage. The AD1991 is arranged internally as four transistor pairs, which can be used as two H bridge outputs (Two-Channel Mode), or as four single ended outputs (Four-Channel Mode), using either two or four TTL compatible inputs to control the transistors. The output stage can be operated over a range of power supply voltage from 8 V to 20 V. A dead time is automatically provided between the switching of the high side transistor and low side transistor when the control inputs change level to ensure that both the high side transistor and low side transistor are never on at the same time. The part is configured during RESET to be in either two-channel mode or four-channel mode.

To protect the IC as well as the connected speakers, the AD1991 provides turn-on and turn-off pop suppression, short circuit protection and overtemperature shut down. To control the IC, a Power Down/Reset input plus a mute pin are available.

Pricing and Availability
The AD1991 Class D Output Stage is available in a 52-pin TQFP package and is rated for the industrial -40°C to +85°C temperature range. The AD1991 is in Production, and Samples are available. Prices begin at $7.91 in 1,000-piece quantities.

Part#	Offset Voltage (µV)	Offset Voltage Tempco	Gain	Gain Match	Noise Voltage Density	Offset Current (nA)	Breakdown Voltage (V)	Col-Base lkg cur (pA)	Col-Col lkg Current (pA)	Col-Emit lkg Current (pA)	Temp Range (°C)	Package	Price* (1000-4999)
MAT01	100	0.5µV/C	500	3%	7.5nV/rthz	0.6	45	50	200	200	-55 to 125	TO-78	$5.93
MAT02	50	0.3µV/C	500	2%	1nV/rthz	0.6	40	200	200	200	-55 to 125	TO-78	$6.27
MAT03	100	0.5µV/C	100	3%	0.7nV/rthz	35	36	200	n/a	n/a	-40 to 85	TO-78	$7.66
MAT04	200	1µV/C	400	2%	2.5nV/rthz	5	40	5	n/a	n/a	-40 to 85	GSCdip-P-dip and Soic	$3.91

* The pricing listed here is provided only for budgetary purposes as recommended list price in U.S. Dollars in the United States ex factor per unit for the stated volume. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.
** Pricing is currently unavailable. Click on the product number to see the Product Page for additional information.

The model number is a specific version of a generic that can be purchased or sampled.

Status indicates the current lifecycle of the product. This can be one of 4 stages:

• Pre-Release: The model has not been released to general production, but samples may be available.
• Production: The model is currently being produced, and generally available for purchase and sampling.
• Last Time Buy: The model has been scheduled for obsolescence, but may still be purchased for a limited time.
• Obsolete: The specific part is obsolete and no longer available. Other models listed in the table may still be available (if they have a status that is not obsolete).

The package for this IC (i.e. DIP, SOIC, BGA). An Evaluation Board is a board engineered to show the performance of the model, the part is included on the board.

For detailed drawings and chemical composition please consult our  Package Site

Pin Count is the number of pins, balls, or pads on the device. Pin-out diagrams & pin function descriptions may be found in the datasheet.

This is the acceptable operating range of the device. The various ranges specified are as follows:

• Commercial: 0 to +70 degrees Celsius
• Military : -55 to +125 degrees Celsius
• Industrial: Temperature ranges may vary by model. Please consult the datasheet for more information.
• Automotive: -40 to +125 degrees Celsius

The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.

This is the date Analog Devices, Inc. anticipates that the product will ship from the warehouse. Most orders ship within 48 hours of this date.Once an order has been placed, Analog Devices, Inc. will send an Order Acknowledgement email to confirm your delivery date. It is important to note the scheduled dock date on the order entry screen. We do take orders for items that are not in stock, so delivery may be scheduled at a future date. Also, please note the warehouse location for the product ordered. We have warehouses in the United States, Europe and Southeast Asia. Transit times from these sites may vary.

Due to environmental concerns, ADI offers many of our products in lead-free versions. For more information about lead-free parts, please consult our Pb (Lead) free information page.