Features

conform to TIA/EIA-232-E and CCITT V.28 specifications

] Low power requirements-maximum 20 ma

stop mode-maximum ICX 10μA

Status

Running speed is as high as 128 kbps-compatible LAP LINK

flowing through the foot

ensure the minimum turn rate of 4V/μs.

Interoperability with+5V UART

Provide 28 -drawing SSOP EIAJ II encapsulation

Instructions

DS14C335

is a three-wheel drive, five receiver equipment, which meets the standard specifications of TIA/EIA-232-E and CCITT V.28. The device uses an internal DC-DC converter to generate the necessary output level from the+3.3V power supply. The shutdown (SD) mode reduces the power current to a maximum of 10 μA. In the SD mode, a receiver is in a state of activity and allows the ring indicator (RI) to minimize the availability of a narrowing small -shaped packaging (SSOP) in the space of the circular indicator (RI).

The low power consumption and small size of the device make it an ideal choice for laptops and laptop applications.

Wiring chart

function figure

These devices have limited built -in ESD protection. During the storage or handling process, the lead should be connected together, or the device should be placed in the conductive foam to prevent static electricity damage to the MOS door.

Parameter measurement information

Tube feet instructions

VCC (pin 3) : Equipment power quotes,+3.3V (± 0.3V).

V+(pinna 1): Tia/EIA-232-E driver's positive power supply. Recommended external capacitors -0.47μF (16V). This power supply is not used for external loading.

V (pin 25): negative power supply of TIA/EIA-232-E drive. Recommended external capacitors -0.47μF (16V). This power supply is not used for external loading.

C1+, C1 Recommended capacitor-0.47μF (6.3V).

C2+, C2 (pinna 2, 4): external capacitor connection pins. Recommended capacitor-0.47μF (16V).

C3+, C3 (Pixels 28, 26): External capacitor connection pins. Recommended capacitor-0.47μF (6.3V).

Shut off (SD) (pin 23): The high level on the shutdown pin will reduce the total ICC current below 10 μA, thereby providing a low power consumption state. In this mode, the receiver R5 keeps activating. The SD pin should be driven or tied (GND) to disable the shutdown mode.

DIN 1 -3 (needle pin 7, 8, 9): The driver input pins are compatible with Jedec 3.3V standards.

DOUT 1 -3 (needle pin 22, 21, 20): The driver output pins conform to the TIA/ELA-232-E grade.

RIN 1 –5 (needle 19, 18, 17, 16, 15): The receiver input pins to receive TIA/EIA-232-E input voltage (± 25V). The receiver specifies the lag of TBD MV. The input pin of the unused receiver may be kept open. Internal input resistance (5 kΩ) pulls the input to provide high output of fault protection.

Path 1 —5 (pin 10, 11, 12, 13, 14): The receiver output pins are compatible with Jedec 3.3V standards.

GND (needle 27): ground pins.

Application information

9 -pin -serial port application

9 -pin actual interface implementation from typical data terminal devices (DTE) to data circuit terminal devices (DCE) Among them, 2 data cables and 6 control cables are needed. The data cable is TXD and RXD, and the control line is RTS, DTR, DSR, DCD, CTS and RI. DS14C335 is a 3 X 5 drive/receiver, which provides a single -chip solution for the DTE interface, as shown in Figure 10.

The ringing indicator (RI) is used to notify DTE a call from the remote DCE. When the DS14C335 is in a shutdown (SD) mode, the receiver 5 (R5) is maintained and monitored the RI circuit. This activity receiver (R5) warned DTE to switch DS14C335 from the shutdown mode to the activity mode.

Mouse driver

DS14C335 under the driver of the mouse driver test:

On VOH, their output is connected to oneStarting (parallel), the source current is V+terminal power supply for mouse electronic equipment

a driver output set to VOL to absorb the current of the v-terminal of the mouse

# 8226; Use a receiver to receive data from the mouse

power supply voltage (VCC): 3.0V to 3.6V

Complete the test (TI data transmission application group and a family The main PC manufacturer is executed) concluded that DS14C335 and its DC-DC converter provides sufficient driving capabilities to drive a typical PC mouse. The test mice were specified under the following conditions:

+6V at 10mA

-6V at 5.0ma

Since the driver current is limited, it is recommended The application specifies a new low -power mouse. The use of old high -power mouse is a waste of precious battery charging.

The external DC-DC converter component

DS14C335 and its unique DC-DC converter increase the power supply voltage (3.0V) three times to+9.3V, and then convert it to #8722; 9V potential. This unique converter only requires 0.47 μF capacitors to install 5 outer surfaces. In order to simplify the layout of PCB and the procurement of components, five identical components were selected. The DS14C335 DC-DC converter also provides a larger signal swing (higher at the RS-232 standard data rate), which is compared with other DC-DC converter solutions that only provide limited signal swings and limited noise. Compared with the latter, it can be converted to a larger noise tolerance to suppress the electrocompany difference, induction noise and string disturbance.

DC-DC converter capacitor

No need to use polarized capacitors. However, if they use them, they must abide by the polarity indicated in the DS14C335 function diagram in order to operate correctly. You can use the surface stickers or ceramic capacitors, but in order to obtain the best efficiency, a capacitor with a low -effective series resistance (ESR) should be used. Usually accept low Ohm (ω) value.

Interoperability of+5V UART

DS14C335 provides a complete RS-232 driver output level, and provides a single-chip solution for the popular 9-shot FAACTO serial port. This device can be used for pure+3V applications or mixed power supply+3V/+5V applications. The driver input (DIN) and the switch (SD) input pin can directly accept the full+5V level without any external components. When the source is 1MA, the receiver output (ROUT) specifies the minimum 2.4V. This level is compatible with standard TTL thresholds. For a complete discussion on DS14C335 and+5V UART , please refer to the TI application instructions An-876 (SNLA163).

Power consumption in the actual RS-232 application

DS14C335 DC-DC converter uses special circuits to help limit the power current that increases as the frequency increases.For a complete explanation of the power consumption and computing of the RS-232 application, see the TI application annotation AN-914 (SNLA037), the title is Understanding the Power Requirement in the RS-232 application .This data table also provides a typical performance curve for fast reference.

Typical performance features