Overview
The MM5452V, produced by National Semiconductor (now part of Texas Instruments), is a monolithic integrated circuit designed to drive liquid crystal displays (LCDs). This device is particularly suited for operating 4½-digit 7-segment displays with minimal interface between the display and the data source. It utilizes CMOS metal gate, low threshold enhancement mode technology and is available in a 40-pin PLCC package.
The MM5452V is capable of driving up to 32 segments of an LCD and can be paralleled to increase this number. It stores display data in latches after it is clocked in and holds the data until new display data is received. This device does not contain a character generator, so the formatting of the segment information must be done prior to inputting the data.
Key Specifications
| Parameter | Conditions | Min | Typ | Max | Units |
|---|---|---|---|---|---|
| Supply Voltage, VDD | 3 | 10 | V | ||
| Average Supply Current, IDD | VDD = 5V, All Outputs Open, Clock=Gnd, Data=Gnd, OSC=Gnd, BP_IN @ 32Hz | 10 | 40 | µA | |
| Input Logical '0' Voltage, VIL | VDD = 3V | 0.4 | 0.8 | V | |
| Input Logical '1' Voltage, VIH | VDD = 3V | 2.0 | 8.0 | V | |
| Segment Sink Current, IOL | VDD = 3V, VOUT = 0.3V | -20 | -40 | µA | |
| Segment Source Current, IOH | VDD = 3V, VOUT = 2.7V | 20 | 40 | µA | |
| Backplane Out Sink Current, IOL | VDD = 3V, VOUT = 0.3V | -320 | -500 | µA | |
| Backplane Out Source Current, IOH | VDD = 3V, VOUT = 2.7V | 320 | 500 | µA | |
| Operating Temperature | -40 | 85 | °C | ||
| Storage Temperature | -65 | 150 | °C | ||
| Power Dissipation at 25°C | 350 | mW | |||
| Power Dissipation at 70°C | 300 | mW | |||
| Junction Temperature | 150 | °C | |||
| Lead Temperature (Soldering, 10s) | 300 | °C |
Key Features
- Serial Data Input: Data transfer is accomplished with two signals: serial data and clock.
- No Load Signal Required: Data transfer without an additional load signal.
- DATA ENABLE (MM5452): The MM5452 uses a DATA ENABLE signal instead of the 33rd output.
- Wide Power Supply Operation: Operates with a supply voltage range of 3V to 10V.
- TTL Compatibility: Compatible with TTL logic levels.
- 32 or 33 Outputs: Can drive up to 32 segments of an LCD, with the option for a 33rd output in the MM5453 model.
- Alphanumeric and Bar Graph Capability: Supports both alphanumeric and bar graph displays.
- Cascaded Operation Capability: Can be cascaded to drive more segments.
Applications
- COPS™ or Microprocessor Displays: Suitable for displays controlled by microprocessors or other digital systems.
- Industrial Control Indicator: Used in industrial control panels for displaying various parameters.
- Digital Clock, Thermometer, Counter, Voltmeter: Ideal for a variety of digital measurement and display devices.
- Instrumentation Readouts: Used in various instrumentation applications for clear and accurate display of data.
- Remote Displays: Can be used in remote display applications where data needs to be transmitted over a few wires.
Q & A
- What is the primary function of the MM5452V?
The primary function of the MM5452V is to drive liquid crystal displays (LCDs), particularly 4½-digit 7-segment displays.
- What is the package type of the MM5452V?
The MM5452V is available in a 40-pin PLCC (Plastic Leaded Chip Carrier) package.
- What is the operating voltage range of the MM5452V?
The MM5452V operates with a supply voltage range of 3V to 10V.
- Does the MM5452V require a load signal for data transfer?
No, the MM5452V does not require a load signal for data transfer.
- How many segments can the MM5452V drive?
The MM5452V can drive up to 32 segments of an LCD.
- Can the MM5452V be cascaded?
Yes, the MM5452V can be cascaded to drive more segments.
- What are some common applications of the MM5452V?
Common applications include COPS™ or microprocessor displays, industrial control indicators, digital clocks, thermometers, counters, voltmeters, instrumentation readouts, and remote displays.
- How does the MM5452V handle data input?
The MM5452V uses serial data input with a clock signal to transfer data. A start bit precedes the 32 data bits, and the data is latched after the 36th clock pulse.
- Can the MM5452V use an external clock?
Yes, the MM5452V can use an externally supplied clock, provided it has a duty cycle of 50%.
- What is the significance of the DATA ENABLE signal in the MM5452V?
The DATA ENABLE signal is used in the MM5452 model instead of the 33rd output. If not required, the 33rd output can be brought out, which is the case in the MM5453 model.
