HMCAD1040-40 v01.0411 Dual 10-Bit 20/40 MSPS A/D Converter Features General Description * 10-bit Resolution The HMCAD1040-40 is a high performance low power dual analog-to-digital converter (ADC). The ADC employs internal reference circuitry, a CMOS control interface, CMOS output data and is based on a proprietary structure. Digital error correction is employed to ensure no missing codes in the complete full scale range. * 20/40 MSPS Maximum Sampling Rate * Ultra-Low Power Dissipation: 24/43 mW * 61.6 dB SNR @ 8 MHz * Internal Reference Circuitry * 1.8 V Core Supply Voltage * 1.7 - 3.6 V I/O Supply Voltage * Parallel CMOS Output A / D Converters - SMT 0 * 9 x 9 mm 64-Pin QFN (LP9E) Package * Dual Channel Typical Applications * Medical Imaging * Portable Test Equipment * Digital Oscilloscopes * IF Communication Several idle modes with fast startup times exist. Each channel can be independently powered down and the entire chip can either be put in Standby Mode or Power Down mode. The different modes are optimized to allow the user to select the mode resulting in the lowest possible energy consumption during idle mode and startup. The HMCAD1040-40 has a highly linear THA optimized for frequencies up to Nyquist. The differential clock interface is optimized for low jitter clock sources and supports LVDS, LVPECL, sine wave and CMOS clock inputs. Pin compatible with HMCAD1040-80, HMCAD1050-40 and HMCAD1050-80. Functional Diagram Figure 1.Functional Block Diagram 0-1 For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 978-250-3343 tel * 978-250-3373 fax * Order On-line at www.hittite.com Application Support: apps@hittite.com HMCAD1040-40 v01.0411 Dual 10-Bit 20/40 MSPS A/D Converter Electrical Specifications DC Electrical Specifications AVDD= 1.8V, DVDD= 1.8V, DVDDCK= 1.8V, OVDD= 2.5V, 20/40 MSPS clock, 50% clock duty cycle, -1 dBFS 8 MHz input signal, unless otherwise noted Parameter Condition Min. Typ. Max. Units 6 %FS DC Accuracy No missing codes Offset error Gain error Guaranteed Mid-scale offset 1 Full scale range deviation from typical LSB Gain matching between channels. 3 sigma value at worst case conditions 0.5 DNL Differential nonlinearity 0.15 LSB INL Integral nonlinearity 0.2 LSB Common mode voltage output VAVDD/2 V Gain matching VCM %FS 0 Input common mode Full scale range Input capacitance Bandwidth Analog input common mode voltage VCM -0.1 Differential input voltage range VCM +0.2 2.0 Differential input capacitance V Vpp 2 pF Input Bandwidth 500 MHz Core Supply Voltage Supply voltage to all 1.8V domain pins. See Pin Configuration and Description 1.7 1.8 2.0 V I/O Supply Voltage Output driver supply voltage (OVDD). Should be higher than or equal to Core Supply Voltage (VOVDD VDVDD) 1.7 2.5 3.6 V Power Supply For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 978-250-3343 tel * 978-250-3373 fax * Order On-line at www.hittite.com Application Support: apps@hittite.com A / D Converters - SMT Analog Input 0-2 HMCAD1040-40 v01.0411 Dual 10-Bit 20/40 MSPS A/D Converter AC Electrical Specifications - 20 MSPS AVDD= 1.8V, DVDD= 1.8V, DVDDCK= 1.8V, OVDD= 2.5V, FS= 20 MSPS clock, 50% clock duty cycle, -1 dBFS 8 MHz input signal, unless otherwise noted. Parameter Performance SNR SNDR A / D Converters - SMT 0 SFDR HD2 HD3 ENOB Crosstalk Condition Signal to Noise Ratio FIN = 2 MHz FIN = 8 MHz FIN =~ FS/2 FIN = 20 MHz Signal to Noise and Distortion Ratio FIN = 2 MHz FIN = 8 MHz FIN =~ FS/2 FIN = 20 MHz Spurious Free Dynamic Range FIN = 2 MHz FIN = 8 MHz FIN =~ FS/2 FIN = 20 MHz Second order Harmonic Distortion FIN = 2 MHz FIN = 8 MHz FIN =~ FS/2 FIN = 20 MHz Min. 60 60 70 -80 Max. Units 61.7 61.6 61.6 61.6 dBFS dBFS dBFS dBFS 61.7 61.6 60.5 61.6 dBFS dBFS dBFS dBFS 80 81 70 80 dBc dBc dBc dBc -90 -90 -90 -90 dBc dBc dBc dBc -80 -81 -70 -80 dBc dBc dBc dBc 10.0 9.9 9.8 9.9 bits bits bits bits -105 dB Third order Harmonic Distortion FIN = 2 MHz FIN = 8 MHz FIN =~ FS/2 FIN = 20 MHz Effective number of Bits FIN = 2 MHz FIN = 8 MHz FIN =~ FS/2 FIN = 20 MHz Signal crosstalk between channels, FIN1=8MHz, FIN0=9.9MHz -70 9.7 Power Supply Analog supply current Digital supply current Output driver supply Output driver supply Digital core supply 2.5V output driver supply, sine wave input, FIN = 1 MHz, CK_EXT enabled 2.5V output driver supply, sine wave input, FIN = 1 MHz, CK_EXT disabled Analog power Dissipation Digital power Dissipation Total power Dissipation Power Down Dissipation Sleep Mode 1 Sleep Mode 2 Clock Inputs Max. Conversion Rate Min. Conversion Rate 0-3 Typ. OVDD = 2.5V, 5pF load on output bits, FIN = 1 MHz, CK_EXT disabled OVDD = 2.5V, 5pF load on output bits, FIN = 1 MHz, CK_EXT disabled Power Dissipation, Sleep mode one channel Power Dissipation, Sleep mode both channels 8.2 mA 1.7 mA 2.8 mA 2.3 mA 14.8 mW 8.8 mW 23.6 mW 9.9 15.2 7.7 mW mW mW 20 3 MSPS MSPS For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 978-250-3343 tel * 978-250-3373 fax * Order On-line at www.hittite.com Application Support: apps@hittite.com HMCAD1040-40 v01.0411 Dual 10-Bit 20/40 MSPS A/D Converter AC Electrical Specifications - 40 MSPS AVDD= 1.8V, DVDD= 1.8V, DVDDCK= 1.8V, OVDD= 2.5V, FS= 40 MSPS clock, 50% clock duty cycle, -1 dBFS 8 MHz input signal, unless otherwise noted. SNDR SFDR HD2 HD3 ENOB Crosstalk Condition Signal to Noise Ratio FIN = 2 MHz FIN = 8 MHz FIN =~ FS/2 FIN = 30 MHz Signal to Noise and Distortion Ratio FIN = 2 MHz FIN = 8 MHz FIN =~ FS/2 FIN = 30 MHz Spurious Free Dynamic Range FIN = 2 MHz FIN = 8 MHz FIN =~ FS/2 FIN = 30 MHz Second order Harmonic Distortion FIN = 2 MHz FIN = 8 MHz FIN =~ FS/2 FIN = 30 MHz Min. 60 60 70 -80 Typ. Max. Units 61.6 61.6 61.6 61.6 dBFS dBFS dBFS dBFS 61.6 61.6 61.2 61.4 dBFS dBFS dBFS dBFS 80 81 72 80 dBc dBc dBc dBc -90 -90 -85 -85 dBc dBc dBc dBc -80 -81 -72 -80 dBc dBc dBc dBc 9.9 9.9 9.8 9.9 bits bits bits bits -100 dB 14.4 mA Third order Harmonic Distortion FIN = 2 MHz FIN = 8 MHz FIN =~ FS/2 FIN = 30 MHz Effective number of Bits FIN = 2 MHz FIN = 8 MHz FIN =~ FS/2 FIN = 30 MHz Signal crosstalk between channels, -70 9.7 FIN1 = 8 MHz, FIN0 = 9.9 MHz Power Supply Analog supply current Digital supply current Output driver supply Output driver supply Digital core supply 2.5V output driver supply, sine wave input, FIN = 1 MHz, CK_EXT enabled 2.5V output driver supply, sine wave input, FIN = 1 MHz, CK_EXT disabled Analog power Dissipation Digital power Dissipation Total power Dissipation Power Down Dissipation Sleep Mode 1 Sleep Mode 2 Clock Inputs Max. Conversion Rate Min. Conversion Rate OVDD = 2.5V, 5pF load on output bits, FIN = 1 MHz, CK_EXT disabled OVDD = 2.5V, 5pF load on output bits, FIN = 1 MHz, CK_EXT disabled Power Dissipation, Sleep mode one channel Power Dissipation, Sleep mode both channels 3.4 mA 5.1 mA 4.2 mA 25.9 mW 16.6 mW 42.5 mW 9.7 25.7 11.3 mW mW mW 40 3 0 A / D Converters - SMT Parameter Performance SNR MSPS MSPS For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 978-250-3343 tel * 978-250-3373 fax * Order On-line at www.hittite.com Application Support: apps@hittite.com 0-4 HMCAD1040-40 v01.0411 Dual 10-Bit 20/40 MSPS A/D Converter Digital & Timing Specifications AVDD= 1.8V, DVDD= 1.8V, DVDDCK= 1.8V, OVDD= 2.5V, Conversion Rate: Max specified, 50% clock duty cycle, -1dBFS input signal, 5 pF capacitive load on data outputs, unless otherwise noted Parameter Condition Min Typ Max Unit 80 % high Clock Inputs Duty Cycle 20 Compliance Input range Differential input swing 0.4 Vpp Input range Differential input swing, sine wave clock input 1.6 Vpp Keep voltages within ground and voltage of OVDD 0.3 Input common mode voltage A / D Converters - SMT 0 CMOS, LVDS, LVPECL, Sine Wave Input capacitance Differential VOVDD -0.3 2 V pF Timing TPD Start up time from Power Down Mode to Active Mode 900 clock cycles TSLP Start up time from Sleep Mode to Active Mode 20 clock cycles TOVR Out of range recovery time 1 TAP Aperture Delay 0.8 ns Aperture jitter < 0.5 ps rms TLAT Pipeline Delay clock cycles 12 clock cycles TD Output delay (see timing diagram). 5pF load on output bits 3 10 ns TDC Output delay relative to CK_EXT (see timing diagram) 1 6 ns VHI High Level Input Voltage. VOVDD 3.0V 2 Logic Inputs V VHI High Level Input Voltage. VOVDD = 1.7V - 3.0V 0.8 *VOVDD VLI Low Level Input Voltage. VOVDD 3.0V 0 0.8 V V VLI Low Level Input Voltage. VOVDD = 1.7V - 3.0V 0 0.2 *VOVDD V IHI High Level Input leakage Current 10 A ILI Low Level Input leakage Current 10 A CI Input Capacitance 3 pF Logic Outputs VHO High Level Output Voltage VOVDD -0.1 V VLO Low Level Output Voltage 0.1 V CL Max capacitive load. Post-driver supply voltage equal to pre-driver supply voltage VOVDD = VOCVDD 5 pF CL Max capacitive load. Post-driver supply voltage above 2.25V [1] 10 pF [1] The outputs will be functional with higher loads. However, it is recommended to keep the load on output data bits as low as possible to keep dynamic currents and resulting switching noise at a minimum 0-5 For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 978-250-3343 tel * 978-250-3373 fax * Order On-line at www.hittite.com Application Support: apps@hittite.com HMCAD1040-40 v01.0411 Dual 10-Bit 20/40 MSPS A/D Converter Timing Diagram Figure 2.Timing Diagram Table 1. Absolute Maximum Ratings Pin Pin Pin AVDD AVSS -0.3V to +2.3V DVDD DVSS -0.3V to +2.3V AVSS, DVSSCK, DVSS, OVSS DVSS -0.3V to +0.3V OVDD OVSS -0.3V to +3.9V IPx, INx, analog inputs and outputs AVSS -0.3V to +2.3V Digital outputs OVSS -0.3V to +3.9V CKP, CKN Digital Inputs DVSSCK -0.3V to +3.9V OVSS -0.3V to +3.9V Operating temperature -40 to +85 C Storage temperature -60 to +150 C Soldering Profile Qualification ELECTROSTATIC SENSITIVE DEVICE OBSERVE HANDLING PRECAUTIONS A / D Converters - SMT 0 Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. J-STD-020 For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 978-250-3343 tel * 978-250-3373 fax * Order On-line at www.hittite.com Application Support: apps@hittite.com 0-6 HMCAD1040-40 v01.0411 Dual 10-Bit 20/40 MSPS A/D Converter Pin Configuration and Description A / D Converters - SMT 0 Figure 3.Package Drawing, QFN 64-Pin 0-7 For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 978-250-3343 tel * 978-250-3373 fax * Order On-line at www.hittite.com Application Support: apps@hittite.com HMCAD1040-40 v01.0411 Dual 10-Bit 20/40 MSPS A/D Converter Table 2. Pin Descriptions Function Description 1, 18, 23 DVDD Digital and I/O-ring pre driver supply voltage, 1.8V 2 CM_EXT Common Mode voltage output 3, 9, 12 AVDD Analog supply voltage, 1.8V 4, 5, 8 AVSS Analog ground 6, 7 IP0, IN0 Analog input Channel 0 (non-inverting, inverting) 10, 11 IP1, IN1 Analog input Channel 1 (non-inverting, inverting) 13 DVSSCK Clock circuitry ground 14 DVDDCK Clock circuitry supply voltage, 1.8V 15 CKP Clock input, non-inverting (Format: LVDS, LVPECL, CMOS/TTL, Sine Wave) 16 CKN Clock input, inverting. For CMOS input on CKP, connect CKN to ground. 17, 64 DVSS Digital circuitry ground 19 CK_EXT_EN CK_EXT signal enabled when low (zero). Tristate when high. 20 DFRMT Data format selection. 0: Offset Binary, 1: Two's Complement 21 PD_N Full chip Power Down mode when Low. All digital outputs reset to zero. After chip power up always apply Power Down mode before using Active Mode to reset chip. 22 OE_N_1 Output Enable Channel 0. Tristate when high 24, 41, 58 OVDD I/O ring post-driver supply voltage. Voltage range 1.7 to 3.6V 25, 40, 57 OVSS Ground for I/O ring 26 NC 27 NC 28 NC 29 D1_0 Output Data Channel 1 (LSB) 30 D1_1 Output Data Channel 1 31 D1_2 Output Data Channel 1 32 D1_3 Output Data Channel 1 33 D1_4 Output Data Channel 1 34 D1_5 Output Data Channel 1 35 D1_6 Output Data Channel 1 36 D1_7 Output Data Channel 1 37 D1_8 Output Data Channel 1 38 D1_9 Output Data Channel 1 (MSB) 39 ORNG_1 Out of Range flag Channel 1. High when input signal is out of range Output clock signal for data synchronization. CMOS levels 42 CK_EXT 43 NC 44 NC 45 NC 46 D0_0 Output Data Channel 0 (LSB) 47 D0_1 Output Data Channel 0 48 D0_2 Output Data Channel 0 49 D0_3 Output Data Channel 0 For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 978-250-3343 tel * 978-250-3373 fax * Order On-line at www.hittite.com Application Support: apps@hittite.com 0 A / D Converters - SMT Pin Number 0-8 HMCAD1040-40 v01.0411 Dual 10-Bit 20/40 MSPS A/D Converter Table 2. Pin Descriptions Pin Number Description 50 D0_4 Output Data Channel 0 51 D0_5 Output Data Channel 0 52 D0_6 Output Data Channel 0 53 D0_7 Output Data Channel 0 54 D0_8 Output Data Channel 0 55 D0_9 Output Data Channel 0 (MSB) 56 ORNG_0 Out of Range flag Channel 0. High when input signal is out of range 59 OE_N_0 Output Enable Channel 0. Tristate when high 60, 61 CM_EXTBC_1, CM_ EXTBC_0 Bias control bits for the buffer driving pin CM_EXT 00: OFF 01: 50uA 10: 500uA 11: 1mA 62, 63 SLP_N_1, SLP_N_0 Sleep Mode 00: Sleep Mode 01: Channel 0 active 10: Channel 1 active 11: Both channels active A / D Converters - SMT 0 Function 0-9 For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 978-250-3343 tel * 978-250-3373 fax * Order On-line at www.hittite.com Application Support: apps@hittite.com HMCAD1040-40 v01.0411 Dual 10-Bit 20/40 MSPS A/D Converter Analog Input The analog input to the HMCAD1040-40 is a switched capacitor track-and-hold amplifier optimized for differential operation. Operation at common mode voltages at mid supply is recommended even if performance will be good for the ranges specified. The CM_EXT pin provides a voltage suitable as common mode voltage reference. The internal buffer for the CM_EXT voltage can be switched off, and driving capabilities can be changed by using the CM_EXTBC control input. Figure 4 shows a simplified drawing of the input network. The signal source must have sufficiently low output impedance to charge the sampling capacitors within one clock cycle. A small external resistor (e.g. 22 Ohm) in series with each input is recommended as it helps reduce transient currents and dampens ringing behavior. A small differential shunt capacitor at the chip side of the resistors may be used to provide dynamic charging currents and may improve performance. The resistors form a low pass filter with the capacitor, and values must therefore be determined by requirements for the application. Figure 4. Input configuration DC-Coupling Preferably, the CM_EXT output should be used as reference to set the common mode voltage. The input amplifier could be inside a companion chip or it could be a dedicated amplifier. Several suitable single ended to differential driver amplifiers exist in the market. The system designer should make sure the specifications of the selected amplifier is adequate for the total system, and that driving capabilities comply with the HMCAD1040-40 input specifications. Detailed configuration and usage instructions should be found in the documentation of the selected driver, and the values given in figure 5 must be varied according to the recommendations for the driver. AC-Coupling A signal transformer or series capacitors can be used to make an AC-coupled input network. Figure 6 shows a recommended configuration using a transformer. Make sure that a transformer with sufficient linearity is selected, and that the bandwidth of the transformer is appropriate. The bandwidth should exceed the sampling rate of the ADC with at least a factor of 10. It is also important to minimize phase mismatch between the differential ADC inputs for good HD2 performance. This type of transformer coupled input is the preferred configuration for high frequency signals as most differential amplifiers do not have adequate performance at high frequencies. Magnetic coupling between the transformers and PCB traces may impact channel crosstalk, and must be taken into account during PCB layout. If the input signal is traveling a long physical distance from the signal source to the transformer (for example a long cable), kick-backs from the ADC will also travel along this distance. If these kick-backs are not terminated properly at the source side, they are reflected and will add to the input signal at the ADC input. This could reduce the ADC performance. To avoid this effect, the source must effectively terminate the ADC kick-backs, or the traveling distance should be very short. If this problem could not be avoided, the circuit in figure 8 can be used. 0 A / D Converters - SMT Recommended Usage Figure 5. DC coupled input with buffer Figure 5 shows a recommended configuration for DCcoupling. Note that the common mode input voltage must be controlled according to specified values. Figure 6. Transformer coupled input For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 978-250-3343 tel * 978-250-3373 fax * Order On-line at www.hittite.com Application Support: apps@hittite.com 0 - 10 HMCAD1040-40 v01.0411 Dual 10-Bit 20/40 MSPS A/D Converter Figure 7 shows AC-coupling using capacitors. Resistors from the CM_EXT output, RCM, should be used to bias the differential input signals to the correct voltage. The series capacitor, CI, form the highpass pole with these resistors, and the values must therefore be determined based on the requirement to the high-pass cut-off frequency. The quality of the input clock is extremely important for high-speed, high-resolution ADCs. The contribution to SNR from clock jitter with a full scale signal at a given frequency is shown in equation 1, 0 SNRjitter = 20 * log (2 * * IN * t) A / D Converters - SMT Figure 7. AC coupled input Figure 8. Alternative input network Note that startup time from Sleep Mode and Power Down Mode will be affected by this filter as the time required to charge the series capacitors is dependent on the filter cut-off frequency. If the input signal has a long traveling distance, and the kick-backs from the ADC not are effectively terminated at the signal source, the input network of figure 8 can be used. The configuration in figure 8 is designed to attenuate the kickback from the ADC and to provide an input impedance that looks as resistive as possible for frequencies below Nyquist. Values of the series inductor will however depend on board design and conversion rate. In some instances a shunt capacitor in parallel with the termination resistor (e.g. 33 pF) may improve ADC performance further. This capacitor attenuates the ADC kick-back even more, and minimizes the kicks traveling towards the source. However, the impedance match seen into the transformer becomes worse. Clock Input and Jitter considerations Typically high-speed ADCs use both clock edges to generate internal timing signals. In the HMCAD1040-40 only the rising edge of the clock is used. Hence, input clock duty cycles between 20% and 80% are acceptable. 0 - 11 The input clock can be supplied in a variety of formats. The clock pins are AC-coupled internally. Hence a wide common mode voltage range is accepted. Differential clock sources as LVDS, LVPECL or differential sine wave can be connected directly to the input pins. For CMOS inputs, the CKN pin should be connected to ground, and the CMOS clock signal should be connected to CKP. For differential sine wave clock, the input amplitude must be at least 800 mVpp. (1) where fIN is the signal frequency, and t is the total rms jitter measured in seconds. The rms jitter is the total of all jitter sources including the clock generation circuitry, clock distribution and internal ADC circuitry. For applications where jitter may limit the obtainable performance, it is of utmost importance to limit the clock jitter. This can be obtained by using precise and stable clock references (e.g. crystal oscillators with good jitter specifications) and make sure the clock distribution is well controlled. It might be advantageous to use analog power and ground planes to ensure low noise on the supplies to all circuitry in the clock distribution. It is of utmost importance to avoid crosstalk between the ADC output bits and the clock and between the analog input signal and the clock since such crosstalk often results in harmonic distortion. The jitter performance is improved with reduced rise and fall times of the input clock. Hence, optimum jitter performance is obtained with LVDS or LVPECL clock with fast edges. CMOS and sine wave clock inputs will result in slightly degraded jitter performance. If the clock is generated by other circuitry, it should be re-timed with a low jitter master clock as the last operation before it is applied to the ADC clock input. Digital Outputs Digital output data are presented in parallel CMOS form. The voltage on the OVDD pin sets the levels of the CMOS outputs. The output drivers are dimensioned to drive a wide range of loads for OVDD above 2.25V, but it is recommended to minimize the load to ensure as low transient switching currents and resulting noise as possible. In applications with a large fanout or large For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 978-250-3343 tel * 978-250-3373 fax * Order On-line at www.hittite.com Application Support: apps@hittite.com HMCAD1040-40 v01.0411 Dual 10-Bit 20/40 MSPS A/D Converter capacitive loads, it is recommended to add external buffers located close to the ADC chip. The timing is described in the Timing Diagram section. Note that the load or equivalent delay on CK_EXT always should be lower than the load on data outputs to ensure sufficient timing margins. The digital outputs can be set in tristate mode by setting the OE_N signal high. The HMCAD1040-40 employs digital offset correction. This means that the output code will be 4096 with shorted inputs. However, small mismatches in parasitics at the input can cause this to alter slightly. The offset correction also results in possible loss of codes at the edges of the full scale range. With no offset correction, the ADC would clip in one end before the other, in practice resulting in code loss at the opposite end. With the output being centered digitally, the output will clip, and the out of range flags will be set, before max code is reached. When out of range flags are set, the code is forced to all ones for overrange and all zeros for underrange. Data Format Selection The output data are presented on offset binary form when DFRMT is low (connected to OVSS). Setting DFRMT high (connected to OVDD) results in 2's complement output format. Details are shown in table 3. 0 Differential Input Voltage (IPx - INx) Output data: Dx_9 : Dx_0 (DFRMT = 0, offset binary) Output Data: Dx_9 : Dx_0 (DFRMT = 1, 2's complement) 1.0 V 11 1111 1111 01 1111 1111 +0.24mV 10 0000 0000 00 0000 0000 -0.24mV 01 1111 1111 11 1111 1111 -1.0V 00 0000 0000 10 0000 0000 Reference Voltages The reference voltages are internally generated and buffered based on a bandgap voltage reference. No external decoupling is necessary, and the reference voltages are not available externally. This simplifies usage of the ADC since two extremely sensitive pins, otherwise needed, are removed from the interface. Operational Modes The operational modes are controlled with the PD_N and SLP_N pins. If PD_N is set low, all other control pins are overridden and the chip is set in Power Down mode. In this mode all circuitry is completely turned off and the internal clock is disabled. Hence, only leakage current contributes to the Power Down Dissipation. The startup time from this mode is longer than for other idle modes as all references need to settle to their final values before normal operation can resume. The input clock should be kept running in all idle modes. However, even lower power dissipation is possible in Power Down mode if the input clock is stopped. In this case it is important to start the input clock prior to enabling active mode. Startup Initialization The HMCAD1040-40 must be reset prior to normal operation. This is required every time the power supply voltage has been switched off. A reset is performed by applying Power Down mode. Wait until a stable supply voltage has been reached, and pull the PD_N pin for the duration of at least one clock cycle. The input clock must be running continuously during this Power Down period and until active operation is reached. Alternatively the PD pin can be kept low during power-up, and then be set high when the power supply voltage is stable. A / D Converters - SMT Table 3: Data Format Description for 2Vpp full scale range The SLP_N bus can be used to power down each channel independently, or to set the full chip in Sleep Mode. In this mode internal clocking is disabled, but some low bandwidth circuitry is kept on to allow for a short startup time. However, Sleep Mode represents a significant reduction in supply current, and it can be used to save power even for short idle periods. For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 978-250-3343 tel * 978-250-3373 fax * Order On-line at www.hittite.com Application Support: apps@hittite.com 0 - 12 HMCAD1040-40 v01.0411 Dual 10-Bit 20/40 MSPS A/D Converter Outline Drawing A / D Converters - SMT 0 Table 4. 9x9mm QFN (64 Pin LP9) Dimensions Symbol Millimeter Min Typ A A1 0.01 0.05 A2 0.65 0.7 A3 0.2 REF b Min Typ 0.9 0 0.2 D 0.25 0 3.79 L 0.3 e 0.3 0.008 0 F 1.9 G 0.24 0.002 0.026 0.028 0.01 0.012 0.354 bsc 0.344 bsc 3.99 4.19 0.149 0.4 0.5 0.012 0.50 bsc 1 0.0004 0.008 REF 8.75 bsc D2 Max 0.035 9.00 bsc D1 0 - 13 Inch Max 0.157 0.165 0.016 0.02 0.020 bsc 12 0 12 0.075 0.42 0.6 0.0096 0.0168 0.024 For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 978-250-3343 tel * 978-250-3373 fax * Order On-line at www.hittite.com Application Support: apps@hittite.com HMCAD1040-40 v01.0411 Dual 10-Bit 20/40 MSPS A/D Converter Package Information Part Number Package Body Material Lead Finish MSL [1] Package Marking [2] HMCAD1040-40 RoHS-compliant Low Stress Injection Molded Plastic 100% matte Sn Level 2A ASD0400 XXXX XXXX [1] MSL, Peak Temp: The moisture sensitivity level rating classified according to the JEDEC industry standard and to peak solder temperature. [2] Proprietary marking XXXX, 4-Digit lot number XXXX A / D Converters - SMT 0 For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 978-250-3343 tel * 978-250-3373 fax * Order On-line at www.hittite.com Application Support: apps@hittite.com 0 - 14