Part Number: LC7821
Function: Analog Function Switch
Package: DIP 30 Pin Type
Manufacturer: Sanyo
Images
Description
The LC7821 is a serial data-controlled analog function switch designed for signal routing in amplifiers, receivers, and other analog audio equipment. It contains two groups of eight analog switches, provides a wide signal range supported by ±20V breakdown capability, and includes serial control, device selection, and reset functions for flexible microcomputer-based operation. Typical applications include audio source selection, amplifier signal routing, receiver input switching, and electronically controlled analog signal paths
Features
- Eight analog switch channels × 2
- Serial data-controlled analog function selection
- Designed for use with 5V-operated microcomputers
- Selector pin allows two ICs of the same type to share a common serial bus
- Reset input turns OFF all analog switches
- Wide dynamic range supported by ±20V breakdown voltage
- Suitable for amplifiers and receivers
- Multiple internal connection configurations available within the LC7821/LC7822/LC7823 family
Pinout
Absolute Maximum Ratings (Tc = 25 °C)
| Parameter | Symbol | Value | Unit |
| Digital input voltage, DI, CL, CE, S, RES | VI | −0.3 to VDD+0.3 | V |
| Analog terminal voltage, L1 to L8, R1 to R8, LCOM1 to LCOM4, RCOM1 to RCOM4 | V | VEE−0.3 to VDD+0.3 | V |
| Analog switch ON-state voltage difference | ΔVON | 0.5 | V |
| Allowable power dissipation | Pdmax | 100 | mW |
| Operating temperature | Topr | −30 to +75 | °C |
| Storage temperature | Tstg | −40 to +125 | °C |
Block Diagram
Working Principle
- The LC7821 functions as an electronically controlled analog switch matrix for routing audio or other analog signals between multiple input and common terminals
- Its two groups of eight switches provide multiple selectable signal paths, making it suitable for stereo source selection in audio equipment
- Switch states are programmed through serial data rather than individual control lines, substantially reducing the number of microcontroller connections required
- The DI, CL, and CE control signals provide the serial interface used to transfer and latch switching information into the device
- The S selector pin allows two devices of the same type to be connected to a common serial bus while providing separate device selection
- The RES reset input can turn OFF all analog switches, providing a defined disconnected state during startup, shutdown, or fault recovery
- The analog switch terminals operate between the VEE and VDD supply rails, allowing the signal path to accommodate a comparatively wide analog voltage range
- The low voltage difference requirement across an ON switch helps maintain the intended analog signal path when the selected channel is active
Applications
- Audio amplifiers
- AM/FM receivers
- Stereo source selectors
- Audio input routing
- Electronically controlled analog signal switching
- Microcomputer-controlled audio equipment
- Receiver signal-path selection
- Analog function selection systems
Alternative / Equivalent Products
- LC7822
- LC7823
LC7821 Datasheet PDF
