El SN74LVC2G74DCUR de Texas Instruments es un flip-flop de tipo D de disparo por flanco positivo con borrado y preajuste as\u00edncronos en un encapsulado VSSOP (DCU) de 8 patillas que mide 2,3\u00d72,0 mm. Funciona de 1,65 V a 5,5 V con un retardo de propagaci\u00f3n m\u00e1ximo de 5,9 ns a 3,3 V y de 4,4 ns a 5 V. El dispositivo dispone de salidas Q y Q complementarias, \u00b124 mA de accionamiento de salida a 3,3 V, corriente de reposo m\u00e1xima de 10 \u00b5A y frecuencia de reloj de hasta 200 MHz. El circuito Ioff soporta aplicaciones de apagado parcial e inserci\u00f3n en vivo. El rango de temperatura de funcionamiento es de -40\u00b0C a +125\u00b0C para el sufijo DCUR.<\/p>","protected":false},"excerpt":{"rendered":"
The SN74LVC2G74DCUR from Texas Instruments is a single positive-edge-triggered D-type flip-flop with asynchronous clear and preset in an 8-pin VSSOP (DCU) package measuring 2.3\u00d72.0 mm. It operates from 1.65 V to 5.5 V with maximum propagation delay of 5.9 ns at 3.3 V and 4.4 ns at 5 V. The device features complementary Q and […]<\/p>\n","protected":false},"author":2,"featured_media":2875,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[13,15],"tags":[],"chip_brand":[138],"class_list":["post-2042","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-integrated-circuits-ics","category-logic-chips","chip_brand-ti"],"acf":{"brief_explanation":"Single D-FF, preset+clear, 1.65-5.5V, 200MHz, 4.4ns@5V, \u00b124mA, VSSOP-8, -40~125\u00b0C","date_code":"","package_case":"VSSOP-8 (DCU) (2.3 x 2.0 x 0.9 mm, 0.5mm pitch)","in_stock":5000,"datasheet":"https:\/\/www.ti.com\/lit\/ds\/symlink\/sn74lvc2g74.pdf","price":"$0.38 (1K+ pcs)","product_introduction":"The SN74LVC2G74 is a single positive-edge-triggered D-type flip-flop from TI's 74LVC logic family, offering asynchronous preset (PRE) and clear (CLR) inputs with complementary Q and Q-bar outputs. Despite the '2G' prefix (indicating a 2-gate device in the LVC family), this part contains a single flip-flop element with both preset and clear \u2014 the '2G' refers to the approximate gate count, not the number of flip-flops.\n\nThe device operates across a wide voltage range of 1.65 V to 5.5 V, making it suitable for mixed-voltage systems. At 5 V, the maximum propagation delay is 4.4 ns with a 50-pF load, and the maximum clock frequency reaches 200 MHz. The setup time is only 1.1 ns and hold time is 500 ps at 5 V, enabling high-speed synchronous designs.\n\nThe asynchronous preset input (PRE, active low) sets Q high regardless of clock and data inputs. The asynchronous clear input (CLR, active low) sets Q low regardless of other inputs. When both PRE and CLR are inactive (high), data at the D input is transferred to Q on the rising edge of CLK. This independent preset\/clear capability is useful for power-on initialization, manual reset, and handshake circuits.\n\nThe Ioff feature disables outputs when VCC is at 0 V, preventing damaging backflow current in partial-power-down and live-insertion applications. The \u00b124-mA output drive at 3.3 V (\u00b132 mA at 5 V) can directly drive LED indicators or interface with TTL-level inputs. The 10-\u00b5A maximum ICC makes the device suitable for always-on logic circuits.\n\nThe VSSOP-8 (DCU) package occupies only 4.6 mm\u00b2 of board area, approximately half the size of the SSOP-8 (DCT) alternative. TI also offers a DSBGA (chip-scale) package (YZP suffix) at 1.91\u00d70.91 mm for ultra-compact designs. The -40\u00b0C to +125\u00b0C operating range (DCUR suffix) supports automotive and industrial applications.","working_principle":"**D Flip-Flop Core:** The SN74LVC2G74 uses CMOS transmission-gate and inverter-based master-slave latch architecture. On the low phase of CLK, the master latch is transparent and tracks the D input. On the rising edge of CLK, the master latch closes and the slave latch opens, transferring the captured D value to the Q output. This edge-triggered behavior ensures that Q changes only once per clock cycle.\n\n**Asynchronous Preset and Clear:** The PRE and CLR inputs bypass the clocked path. When PRE is low, an internal pull-up path forces Q high regardless of CLK and D. When CLR is low, an internal pull-down path forces Q low. Both inputs are level-sensitive and active-low. If both PRE and CLR are asserted simultaneously, both Q and Q-bar go high (invalid state); the last one released determines the final output.\n\n**Ioff Partial Power-Down:** When VCC = 0 V, the Ioff circuitry places all I\/O pins in a high-impedance state. This prevents current from flowing from an external signal (e.g., from a powered device on the same bus) through the SN74LVC2G74's internal ESD diodes to the unpowered VCC rail. This is critical for hot-swap and battery-backup systems where some devices may be powered while others are not.\n\n**Wide-Voltage Operation:** The LVC architecture uses a thin-oxide CMOS process that supports 1.65-V to 5.5-V operation. Input pins accept voltages up to 5.5 V independently of VCC, allowing the device to translate between voltage domains (e.g., 3.3-V input signals with 1.8-V VCC).","pin_description":"
| Pin<\/th> | Name<\/th> | Type<\/th> | Description<\/th><\/tr><\/thead> | ||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1<\/td> | CLK<\/td> | I<\/td> | Clock input; positive-edge triggered; data at D is captured on rising edge; triggering at voltage level, not rise time<\/td><\/tr> | ||||||||||||||||||||||||||||
| 2<\/td> | D<\/td> | I<\/td> | Data input; must meet setup time (1.1ns min at 5V) before CLK rising edge and hold time (500ps) after<\/td><\/tr> | ||||||||||||||||||||||||||||
| 3<\/td> | Q<\/td> | O<\/td> | True output; reflects D value captured on CLK rising edge; \u00b124mA drive at 3.3V<\/td><\/tr> | ||||||||||||||||||||||||||||
| 4<\/td> | GND<\/td> | G<\/td> | Ground; connect to PCB ground plane<\/td><\/tr> | ||||||||||||||||||||||||||||
| 5<\/td> | Q-bar<\/td> | O<\/td> | Complementary output; inverted Q; \u00b124mA drive; both Q and Q-bar available simultaneously<\/td><\/tr> | ||||||||||||||||||||||||||||
| 6<\/td> | CLR<\/td> | I<\/td> | Asynchronous clear (active low); forces Q low and Q-bar high when asserted; overrides CLK and D; do not leave floating<\/td><\/tr> | ||||||||||||||||||||||||||||
| 7<\/td> | PRE<\/td> | I<\/td> | Asynchronous preset (active low); forces Q high and Q-bar low when asserted; overrides CLK and D; do not leave floating<\/td><\/tr> | ||||||||||||||||||||||||||||
| 8<\/td> | VCC<\/td> | P<\/td> | Supply voltage 1.65-5.5V; bypass with 0.1\u00b5F ceramic to GND<\/td><\/tr><\/tbody><\/table>","application_scenarios":"
|