MAX4805/MAX4805A Octal High-Voltage-Protected, Low-Power, Low-Noise Operational Amplifiers The MAX4805 and the MAX4805A differ in terms of General Description input-current noise, input impedance, and voltage gain. The MAX4805/MAX4805A are octal high-voltage-protect- Depending on the equivalent transducer source imped- ed operational amplifiers. These devices are a fully inte- ance, either the MAX4805 or the MAX4805A can be used grated, very compact solution for in-probe amplification to optimize a better noise figure. of echo signals coming from transducers in an ultrasound The MAX4805/MAX4805A are available in the 32-pin system. The use of in-probe buffering improves system TQFN package. All devices are specified for the com- signal-to-noise ratio (SNR) for transducers featuring mercial 0NC to +70NC temperature range. high-output impedance. This results in greater penetra- tion depth and sensitivity. The MAX4805/MAX4805A can Features be adopted in ultrasound probes without any change in the system (scanner machine). Typical applica- S High Density/8 Channels Per Package tions include high-impedance piezoelectric transducers S I/O Protection for TX Burst Up to 100V (PZT) and capacitive micromachined ultrasonic trans- S Very Fast Recovery Time After TX Burst ducers (CMUT) in-probe buffering and amplification. 1.5s (typ) The MAX4805 is optimized for PZT applications, and the S OVP for Signals Greater Than 2.7V (typ) MAX4805A is optimized for CMUT applications. S Extremely Low Power Dissipation 8mW/ch (typ) The MAX4805/MAX4805A feature eight operational amplifiers configured in a noninverting configuration. S 65I (typ) Low-Signal Output Impedance The small-signal output impedance of these operational S 44MHz -3dB Bandwidth (typ) amplifiers is 65I (typ) for matching the typical cable S Voltage Gain 6dB (MAX4805) (typ), 9dB impedance. The low-noise amplifier features 44MHz (MAX4805A) (typ) (typ) -3dB bandwidth and very low voltage and current noise, ensuring excellent noise figure. The output signals S Low Voltage Noise 2.2nV/Hz (typ) (MAX4805) of these operational amplifiers are limited with diodes in S Low Voltage Noise 2.2nV/Hz (typ) (MAX4805A) an antiparallel configuration to GND. S Low Current Noise 2.0pA/Hz (typ) (MAX4805) The MAX4805/MAX4805A provide HV protection for S Low Current Noise 1.7pA/Hz (typ) (MAX4805A) inputs and outputs of the operational amplifiers. The operational amplifiers inputs are protected by an exter- S Ultra-Small (5mm x 5mm), 32-Pin TQFN Package nal HV capacitor. An Functional Diagramsintegrated automatic high-voltage switch protects the output of the amplifier from HV Applications bursts. Transmitted bursts reach the transducer through Ultrasound Medical Imaging, CMUT Probes a pair of integrated, antiparallel diodes. Each channel Ultrasound Medical Imaging, PZT HF Probes is able to sustain transmission burst up to P 100V. The Ultrasound Imaging, PZT NDT Probes high-voltage (HV) protection is automatically activated as soon as the TX voltage is greater than Q2.7V (typ) no dedicated TX/RX signal is required. Ordering Information/Selector Guide VOLTAGE NOISE CURRENT NOISE VOLTAGE GAIN PART APPLICATIONS PIN-PACKAGE (nV/Hz) (pA/Hz) (dB) MAX4805CTJ+ 2.2 2.0 5.7 PZT 32 TQFN-EP* MAX4805ACTJ+ 2.2 1.7 8.7 PZT, CMUT 32 TQFN-EP* Note: All devices are specified over the 0C to +70C operating temperature range. *EP = Exposed pad. +Denotes a lead(Pb)-free/RoHS-compliant package. Pin Configurations appear at end of data sheet. Functional Diagrams continued at end of data sheet. UCSP is a trademark of Maxim Integrated Products, Inc. For pricing, delivery, and ordering information, please contact Maxim Direct 19-5242 Rev 0 4/10 at 1-888-629-4642, or visit Maxims website at www.maxim integrated.com.MAX4805/MAX4805A Octal High-Voltage-Protected, Low-Power, Low-Noise Operational Amplifiers ABSOLUTE MAXIMUM RATINGS (All voltages referenced to GND.) Junction-to-Ambient Thermal Resistance V , V ......................................... (V - 0.3V) to +100V B (Note 1) .................................................................29NC/W TX OUT GSUB JA V - V ........................................................-0.5V to +0.5V Junction-to-Case Thermal Resistance TX OUT V .......................................................................-0.5V to +0.5V B (Note 1) ...................................................................2NC/W IN JC V , V .............................................................-0.3V to +6V Operating Temperature Range ............................. 0NC to +70NC CC1 CC2 V , V ...............................................................-6V to +0.3V Storage Temperature Range ............................ -65NC to +150NC EE1 EE2 GSUB ..................................................................-100V to +0.3V Junction Temperature ................................................... +150NC EN ............................................................................-0.3V to +6V Lead Temperature (soldering, 10s) ................................+300NC Continuous Power Dissipation (T = +70NC) Soldering Temperature (reflow) ......................................+260NC A 32-Pin TQFN (derate 34.5mW/NC above +70NC) ....2758.6mW Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four- layer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial. Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. DC ELECTRICAL CHARACTERISTICS (V = -V = +2V Q2.5%, T = 0NC to +70NC, unless otherwise noted. Typical values are at V = -V = +2V, V = -V = +5V, CC1 EE1 A CC1 EE1 CC2 EE2 T = +25NC.) (Note 2) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Voltage 1 V V = -V 1.95 2 5 V CC1 CC1 EE1 Supply Voltage 2 V V = -V 4.9 5 5.1 V CC2 CC2 EE2 Current consumption from V and V (per channel), CC1 EE1 MAX4805 2.1 3.2 V = -V = +2V, CC1 EE1 V = -V = +5V CC2 EE2 Supply Current I mA CC1 from V and V CC1 EE1 Current consumption from V and V (per channel), CC1 EE1 MAX4805A 1.9 3.0 V = -V = +2V, CC1 EE1 V = -V = +5V CC2 EE2 Supply Current V = -V = +2V, V = -V = +5V CC1 EE1 CC2 EE2 I 25 50 FA CC2 from V and V (per channel) (in reception) CC2 EE2 V = -V = +2V, V = -100V, CC1 EE1 GSUB V = square pulses with Q60V ampli- OUT Substrate Supply Current I tude, f = 5MHz, duty cycle = 2%, 10 FA GSUB PRF = 20kHz, C = 100pF (per channel) EXT (in transmission) V = -V = +2V, CC1 EE1 V = -V = +5V CC2 EE2 MAX4805 8.4 13.2 (per channel) (in reception) (no signal applied) Power Dissipation in Reception PD1 mW V = -V = +2V, CC1 EE1 V = -V = +5V CC2 EE2 MAX4805A 12.2 (per channel) (in reception) (no signal applied) 2 Maxim Integrated