Electronic Components Datasheet Search |
|
EL745 Datasheet(PDF) 10 Page - Elantec Semiconductor |
|
EL745 Datasheet(HTML) 10 Page - Elantec Semiconductor |
10 / 12 page 10 EL7457C 40MHz Non-Inverting Quad CMOS Driver Application Information: Product Description The EL7457C is a high performance 40MHz ultra-high speed quad driver. Each channel of the EL7457C con- sists of a single P-channel high side driver and a single N-channel low side driver. These 3 Ω devices will pull the output (OUTX) to either the high or low voltage, on VH and VL respectively, depending on the input logic signal (INX). It should be noted that there is only one set of high and low voltage pins. A common output enable (OE) pin is available on the EL7457C. This pin, when pulled low will put all outputs in to the high impedance state. The EL7457C is available in both the 16-pin SOIC and the space saving 16-pin QSOP packages. The relevant package should be chosen depending on the calculated power dissipation. Supply Voltage Range and Input Compatibility The EL7457C is designed for operation on supplies from 5V to 15V with 10% tolerance (i.e. 4.5V to 16.5V). The table on page 6 shows the specifications for the relation- ship between the VS+, VS-, VH, VL and GND pins. The EL7457C does not contain a true analog switch and therefore VL should always be less than VH. All input pins are compatible with both 3V and 5V CMOS signals With a positive supply (VS+) of 5V, the EL7457C is also compatible with TTL inputs. Power Supply Bypassing When using the EL7457C, it is very important to use adequate power supply bypassing. The high switching currents developed by the EL7457C necessitate the use of a bypass capacitor on both the positive and negative supplies. It is recommended that a 4.7µ F tantalum capacitor be used in parallel with a 0.1µ F low-induc- tance ceramic MLC capacitor. These should be placed as close to the supply pins as possible. It is also recom- mended that the VH and VL pins have some level of bypassing, especially if the EL7457C is driving highly capacitive loads. Power Dissipation Calculation When switching at high speeds, or driving heavy loads, the EL7457C drive capability is limited by the rise in die temperature brought about by internal power dissipation. For reliable operation die temperature must be kept below Tjmax (125°C). It is necessary to calculate the power dissipation for a given application prior to select- ing the package type. Power dissipation may be calculated: where: • VS is the total power supply to the EL7457C (from VS+ to VS-), • Vout is the swing on the output (VH - VL), • CL is the load capacitance, • CINT is the internal load capacitance (50pF max.), • IS is the quiescent supply current (3mA max.) and • f is frequency Having obtained the application’s power dissipation, a maximum package thermal coefficient may be deter- mined, to maintain the internal die temperature below Tjmax. where: • Tjmax is the maximum junction temperature (125°C), • Tmax is the maximum operating temperature, • PD is the power dissipation calculated above. Using the value of θja, a suitable package for the applica- tion may be selected. In applications with a θja greater than 158°C/W, a 16-pin QSOP may be used. A 16-pin SOIC is suitable for appli- cations with a θja value greater than 110°C/W. However, PD V S I S × () C INT V S 2 × f × () C L V OUT 2 × f × () + 1 4 ∑ + = θ ja T jmax T max – () PD ---------------------------------------- = |
Similar Part No. - EL745 |
|
Similar Description - EL745 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |