Features: ` ESD Protection for RS-232 I/O Pins
±15 kV Human-Body Model (HBM)
±8 kV IEC 61000-4-2, Contact Discharge
±8 kV IEC 61000-4-2, Air-Gap Discharge
` 300-A Operating Supply Current
` 1-A Low-Power Standby (With Receivers Active) Mode
` Designed to Transmit at a Data Rate of 460 kbps
` Auto-Powerdown Plus Option Features Flexible Power-Saving Mode
` Operates From a Single 2.25-V to 3-V VCC SupplyApplication· Battery-Powered Systems
· PDAs
· Cellular Phones
· Notebooks
· Hand-Held Equipment
· PagersPinout
Specifications
| |
MIN |
MAX |
UNIT |
| VCC to GND |
0.3 |
6 |
V |
| V+ to GND(2) |
0.3 |
7 |
V |
| V to GND(2) |
7 |
0.3 |
V |
| V+ + IV-I(2) |
|
13 |
V |
| Input voltage |
DIN, FORCEON,FORCEOFF to GND |
0.3 |
6 |
V |
| RIN to GND |
|
±25 |
V |
| Output voltage |
DOUT to GND |
|
±13.2 |
V |
| ROUT, INVALID, READY to GND |
0.3 |
VCC + 0.3 |
V |
| Short-circuit duration |
DOUT to GND |
|
Continuous |
|
| Continuous power dissipation (TA = 70°C) |
16-pin SSOP (derate 7.14 mW/°C above 70°C) |
|
571 |
mW |
| 20-pin SSOP (derate 8 mW/°C above 70°C |
|
640 |
| 20-pin TSSOP (derate 7 mW/°C above 70°C) |
|
559 |
| Storage temperature range |
65 |
150 |
°C |
| Lead temperature (soldering, 10 s) |
|
300 |
°C |
(1) Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under "recommended operating conditions" is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
(2) V+ and V can have maximum magnitudes of 7 V, but their absolute difference cannot exceed 13 V.
DescriptionThe TRS3318 is a dual-driver, dual-receiver, RS-232 compatible transceiver. The TRS3318 features auto-powerdown plus and enhanced electrostatic discharge (ESD) protection integrated into the chip. Driver output and receiver input are protected to ±8 kV using the IEC 61000-4-2 Air-Gap Discharge method, ±8 kV using the IEC 61000-4-2 Contact Discharge method, and ±15 kV using the Human-Body Model (HBM).
The TRS3318 operates at a data rate of 460 kbps. The transceiver has a proprietary low-dropout driver output stage enabling RS-232-compatible operation from a 2.25-V to 3-V supply with a dual charge pump. The charge pump equires only four 0.1-F capacitors and features a logic-level output (READY) that asserts when the charge pump is regulating and the device is ready to begin transmitting.
The TRS3318 achieves a 1-A supply current using the auto-powerdown feature. This device automatically enters a low-power power-down mode when the RS-232 cable is disconnected or the drivers of the connected eripherals are inactive for more than 30 s. The TRS3318 turns on again when it senses a valid transition at any driver or receiver input. Auto-powerdown saves power without changes to the existing BIOS or operating system.
This TRS3318 is available in two space-saving packages: 20-pin SSOP and 20-pin TSSOP.
Flexible control options for power management are featured when the serial port and driver inputs are inactive.
The auto-powerdown plus of TRS3318 feature functions when FORCEON is low and FORCEOFF is high. During this mode of peration, if the device does not sense valid signal transitions on all receiver and driver inputs for approximately 30 s, the built-in charge pump and drivers are powered down, reducing the supply current to 1 A. By disconnecting the serial port or placing the peripheral drivers off, auto-powerdown plus can be disabled when ORCEON and FORCEOFF are high. With auto-powerdown plus enabled, the device activates automatically when a valid signal is applied to any receiver or driver input. INVALID of TRS3318 is high (valid data) if any receiver input voltage is greater than 2.7 V or less than 2.7 V, or has been between 0.3 V and 0.3 V for less than 30 s (typical number). INVALID of TRS3318 is low (invalid data) if all receiver input voltage are between 0.3 V and 0.3 V for more than 30 s (typical number).
TRS3318 Data Sheet
