ASNT7113A-KHC

Advanced Science And Novel Technology Company, Inc. 2790 Skypark Drive Suite 112, Torrance, CA 90505 Offices: 310-530-9400 / Fax: 310-530-9402 www.adsantec.com ASNT7113A-KHC 4.0GSps / 20GHz Differential Track-and-Hold Amplifier gaincrl vcc varcrl vcc vp0p9 More than 8-bit accuracy within the full frequency range Sampling speed from 50MSps to 4GSps Nominal 0dB differential gain with manual adjustment Adjustable duty cycle of the internal sampling clocks Adjustable input bandwidth Adjustable overall gain Fully differential input and output data and clock buffers with on-chip 50Ohm termination Dual power supply Total power consumption of 1.75W Fabricated in SiGe for high performance, yield, and reliability Custom CQFN 24-pin package vcc            vee vcc vcc dp qp vcc vcc 1 vcc cn vcc vcc vcc cp qn vcc dn t2crl Rev. 1.0.2 ASNT7113A vee March 2021 Advanced Science And Novel Technology Company, Inc. 2790 Skypark Drive Suite 112, Torrance, CA 90505 Offices: 310-530-9400 / Fax: 310-530-9402 www.adsantec.com DESCRIPTION vp0p9 varcrl dp dn cp cn Input Data Equalizer Sampling Strobe Generator data Sampling Output Block Buffer qp qn s1 s2 t2crl gaincrl Fig. 1. Functional Block Diagram The ASNT7113A-KHC SiGe IC is a high-speed, temperature stable, and broadband track-and-hold amplifier (THA) with improved reliability. The IC shown in Fig. 1 performs sampling of an input differential analog signal using two internally-generated strobe signals s1 and s2, and delivers a step-like differential signal to the output. It features an adjustable track period length controlled by the t2crl voltage that modifies the states of internal delay lines. This allows for maximizing the length of the valid output step. The differential gain of the chip is approximately 0dB, which corresponds to a single-ended-to-differential gain of -6dB. The gain can be adjusted using the external control voltage gaincrl. The chip supports both AC-coupled, and DC-coupled inputs. In the DC-coupled mode, the input common-mode voltage must be equal to vcc for optimal performance of the chip. The input sampled data path includes an equalizer that increases the bandwidth of the chip. The level of equalization is controlled by the external voltage varcrl. The frequency response, and gain of the part is also controlled by the positive supply voltage vp0p9 that powers the input buffers of the Track-and-Hold. This voltage defines the common mode of the data signal at the input of the sampling switch, and thus the frequency response of the device. Lower voltages result in less peaking in the input buffer, and less overall gain of the device. The part’s outputs support the CML-type logic interface with an on-chip 50Ohm termination to vcc, and may be used differentially, AC/DC coupled, single-ended, or in any combination (also see POWER SUPPLY CONFIGURATION). The differential DC signaling mode is recommended for optimal performance. Rev. 1.0.2 2 March 2021 Advanced Science And Novel Technology Company, Inc. 2790 Skypark Drive Suite 112, Torrance, CA 90505 Offices: 310-530-9400 / Fax: 310-530-9402 www.adsantec.com Input Data Equalizer The input data’s bandwidth can be adjusted by the internal equalizer controlled with the external voltage varcrl. The equalizer is designed to compensate for the gain drop at high frequencies due to the characteristics of the front-end circuitry, and the sampling block itself. The measured frequency response of the IC at maximum (magenta line) and minimum (orange line) values of the varcrl voltage is shown in Fig. 2. The measurements have been performed at the intermediate setting of the gain control (see Fig. 4). 1 0 Gain, dB -1 -2 -3 -4 -5 0.1 1 VarMAX 10 100 F, GHz VarMIN Fig. 2. Frequency Response of SHA with Max and Min Equalization Input Clock Buffer The input clock buffer converts an external clock cp/cn into two internal signals s1 and s2 with controlled pulse width (PW) as shown in Fig. 3. Track Hold s2 s1 PW  Valid output Fig. 3. Sampling Diagram This allows for optimization of the hold time, and the length of the valid output signal period. The value of PW is reversely proportional to the t2crl voltage. Sampling Block with Output Buffer The sampling block performs conversion of the input signal into a step-like sampled signal under control of s1 and s2 pulses. The sampled signal is amplified by the output buffer to achieve a total gain of approximately 0dB. The gain can be adjusted using the gaincrl voltage signal. The measured frequency response of the SHA with the maximum and minimum gain at 2.5GSps rate is shown in Fig. 4. Rev. 1.0.2 3 March 2021 Advanced Science And Novel Technology Company, Inc. 2790 Skypark Drive Suite 112, Torrance, CA 90505 Offices: 310-530-9400 / Fax: 310-530-9402 www.adsantec.com 1 0 Gain, dB -1 -2 -3 -4 -5 -6 0.1 1 10 100 F, GHz Fig. 4. THA Gain at Max and Min gaincrl Values vs. Data Frequency The harmonic distortion of the THA has been demonstrated by its 3rd harmonic as shown in Fig. 5 for differential clock, and data input signals at the sampling rate of 4GSps. The data amplitude is 125mV differential or 125mV pk-pk at both direct and inverted pins. -5 0 -5 1 -5 2 -5 3 dBc -5 4 -5 5 -5 6 -5 7 -5 8 -5 9 -6 0 0 2 4 6 8 10 12 14 16 18 20 Fdata, GHz Fig. 5. 3-rd Harmonic at 4GHz Input Clock (C) and 125mV Differential Data (D) Amplitude The linearity of the signal conversion is illustrated by Fig. 6 that demonstrates the part’s gain at 2.5GSps. -0.86 -0.88 -0.9 Gain, dB -0.92 -0.94 -0.96 -0.98 -1 -1.02 -1.04 -1.06 0 50 100 150 200 250 300 InputAmplitude SE, mV p-p Fig. 6. THA Gain vs. Input Data Amplitude at Medium State of gaincrl Rev. 1.0.2 4 March 2021 Advanced Science And Novel Technology Company, Inc. 2790 Skypark Drive Suite 112, Torrance, CA 90505 Offices: 310-530-9400 / Fax: 310-530-9402 www.adsantec.com POWER SUPPLY CONFIGURATION The part operates with either a negative supply scheme (vcc = 0.0V = ground), or a positive supply scheme (vee = 0V = ground). In case of the positive supply, all I/Os need AC termination when connected to any devices with 50Ohm termination to ground. Different PCB layouts will be needed for each different power supply combination. ABSOLUTE MAXIMUM RATINGS Caution: Exceeding the absolute maximum ratings shown in Table 1 may cause damage to this product and/or lead to reduced reliability. Functional performance is specified over the recommended operating conditions for power supply and temperature only. AC and DC device characteristics at or beyond the absolute maximum ratings are not assumed or implied. Table 1. Absolute Maximum Ratings Parameter Min Max Units First Supply Voltage (vee) -3.5 (negative scheme) 0 (positive scheme) V Second Supply Voltage (vcc) 0 (negative scheme) 3.5 (positive scheme) V Third Supply Voltage (vp0p9) vcc+1.1 V Power Consumption 2 W RF Input Voltage Swing (Diff) 2.0 V pk-pk Clock Input Voltage Swing (Diff) 1.0 V pk-pk Case Temperature +90 ºC Storage Temperature -40 +100 ºC Operational and storage Humidity 10 98 % TERMINAL FUNCTIONS TERMINAL Name No. Type DESCRIPTION High-Speed I/Os Sampling clock inputs with internal SE 50Ohm termination to vcc Analog Analog sampled data inputs with internal SE 50Ohm input termination to vcc CML output Differential data outputs with internal SE 50Ohm termination to vcc. Require external SE 50Ohm termination to vcc Controls t2crl 1 Analog voltage Sampling clock delay control gaincrl 13 Analog voltage Gain adjustment varcrl 15 Analog voltage Equalizer peaking control Supply and Termination Voltages Name Description Pin Number st vcc 1 positive supply voltage 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24 vee Negative power supply 7, 19 nd vp0p9 2 positive power supply 17 cp cn dp dn qp qn Rev. 1.0.2 3 5 21 23 11 9 CML input 5 March 2021 Advanced Science And Novel Technology Company, Inc. 2790 Skypark Drive Suite 112, Torrance, CA 90505 Offices: 310-530-9400 / Fax: 310-530-9402 www.adsantec.com ELECTRICAL CHARACTERISTICS PARAMETER MAX UNIT COMMENTS General Parameters -3.3 / 0 -3.2 / 0 -3.1 / 0 V Negative scheme / Positive scheme vee 0 / 3.1 0 / 3.2 0 / 3.3 V Negative scheme / Positive scheme vcc 0.75 0.85 0.95 V Above vcc, any scheme vp0p9 Ivcc 430 mA Ivee = Ivcc + Ivp0p9 Ivp0p9 100 mA Power consumption 1750 mW Junction temperature -25 50 125 °C Input Data (dp/dn) Input data frequency 0.0 20 GHz Swing, differential, 0 300 mV 3rd HD