Crystal Units AT-51 / AT-51AD / AT-51CD / AT-51CD2 For Automotive ■ Features d En A crystal unit, ideally suited for the clock signal generating source of the CPUs for power trains and safety control devices, requiring extremity high reliability as part of an automobile’s electronics system. ●Highly reliable under severe environmental conditions in terms of stable start-up characteristics, heat and heat-cycle resistance and vibration resistance. ●A surface-mount crystal unit that due to the resin seating attached to the AT-51 type crystal unit maintains high-level electrical characteristics and reliability. ●AT-51AD, AT-51CD and AT-51CD2 meet the requirements for reflow profiling using lead-free solder. ●AT-51CD2 meets the requirements for re-flow profiling using leadfree solder. AT-51 AT-51AD AT-51CD2 AT-51CD ■ Specifications Model Item Nominal frequency AT-51 / AT-51AD / AT-51CD / AT-51CD2 4 to 25 MHz Overtone order Fundamental ±50 × 10−6 ±150 × 10−6 7 fe 1 Li 20 of arM Frequency tolerance (25 ±3 °C) Frequency versus temperature characteristics (with reference to +25 °C) Operating temperature range −40 to +125 °C Storage temperature range −40 to +125 °C Equivalent series resistance Level of drive Refer to *1 50 μW (Max. 1000 μW) Load capacitance 16 pF The above specifications are standard for this NDK product. Custom-made specifications such as load capacitance and temperature characteristics are also available. Please contact NDK sales with your enquiries. ■ How to Specify an Order When ordering our products, specify them with an “Ordering Code” that consists of the following : Model name - Frequency (Max : 9 digits) M - Number for specifying an order Example AT-51-4.000M-STD-PFE-2 If you have any queries concerning our standard frequencies and numbers for specifying orders, please contact our sales representatives or visit our homepage (http://www.ndk.com/). mm AT-51AD AT-51CD Terminal land connections (TOP VIEW) 5.0max 11.5max 4.88±0.20 11.05max 6.8±0.3 9.0±0.3 2.0±0.2 Land pattern (Typical) 2.4 2.2 5.08±0.2 2.0±0.2 Land pattern (Typical) 3.5 4.4 1.2±0.1 3.5 to 20±1 6.8±0.3 5.08 max 11.5max φ0.43 +0.05 -0.03 mm Terminal land connections (TOP VIEW) 1.5 mm 10.1max 5.2 max AT-51 1.0±0.2 ■ Dimensions 1.0±0.2 1.2±0.2 5.08 10 4.65max 150 4.5 to 6 120 6 to 8 80 8 to 10 70 10 to 25 50 12.4 ±0.3 11.4 ±0.2 Land pattern (Typical) 6.0 2.0 4 to 4.5 mm 0 to 0.3max 3.7max Equivalent Series Resistance max. [Ω] 4.7 ±0.1 Nominal frequency (MHz) 0.65±0.1 5.5±0.3 *1 Equivalent Series Resistance Terminal land connections (TOP VIEW) 10.1max AT-51CD2 4.88±0.2 9.0 cu51_110916_AT-51_e