19-1470; Rev 0; 4/99 900MHz ISM-Band, 250mW Power Amplifiers with Analog or Digital Gain Control The MAX2232/MAX2233 low-voltage, silicon RF power amplifiers (PAs) are designed for use in the 900MHz ISM band. They operate from a single +2.7V to +5.5V supply, allowing them to be powered directly from a 3cell NiCd or a 1-cell Lithium-Ion battery. The devices typically deliver 250mW (+24dBm) of output power at 915MHz from a single +3.6V supply, or 150mW (+22dBm) from a single +2.7V supply. At +24dBm output power, power-added efficiency (PAE) is 44%. The MAX2232/MAX2233 provide 24dB of gain, which is adjustable over a continuous 24dB span via the analog gain-control pin of the MAX2232 or in two 10dB steps via the 2-bit programmable gain-control DAC of the MAX2233. An external capacitor sets the RF output power envelope ramp time, reducing spurious emissions during power-up and power-down by providing a gradual change in output power (MAX2232). The MAX2232/MAX2233 feature a low-power shutdown mode, which typically draws less than 1µA of supply current, saving power during “idle slots” in time-division multiple-access (TDMA) systems. The ∆VSWR of the RF input in shutdown mode relative to normal operation is 1.2:1. The devices also feature a thermal shutdown function, enabling the PA to protect itself from excessive temperature conditions that could damage the IC. A capacitor to ground limits thermal cycling by setting a thermal shutdown timeout period. The MAX2232/MAX2233 are available in a space-saving, thermally enhanced 16-pin power-QSOP (PQSOP) package. Features ♦ 800MHz to 1000MHz Frequency Range ♦ 250mW (+24dBm) Output Power at 915MHz from +3.6V Supply ♦ +2.7V to +5.5V Single-Supply Operation ♦ 44% Power-Added Efficiency ♦ 24dB Power Gain ♦ 24dB Analog Gain-Control Range (MAX2232) ♦ Three Levels of Digitally Programmed Power Gain in 10dB Steps (MAX2233) ♦ Programmable RF Power Envelope Ramping (MAX2232) ♦ Thermal Shutdown ♦ Programmable Thermal Shutdown Timeout Period ♦ 0.2µA Low-Power Shutdown Mode ♦ Low ∆VWSR in Standby and Shutdown Modes Ordering Information PART TEMP. RANGE -40°C to +85°C 16 PQSOP MAX2233EEE -40°C to +85°C 16 PQSOP Pin Configuration Applications 900MHz ISM Band PIN-PACKAGE MAX2232EEE TOP VIEW Digital Cordless Phones Wireless Data FM Analog Transmitters 868MHz European ISM Band RFIN 1 16 VCC GND 2 15 GND 14 RAMP+ (N.C.) SHDN (D1) 3 CTRL (D0) 4 GND 5 MAX2232 MAX2233 13 RAMP- (N.C.) 12 VCC GND 6 11 VCC GND 7 10 TSET 9 RFOUT 8 N.C. Functional Diagram appears at end of data sheet. PQSOP GROUND OF OUTPUT STAGE CONNECTED TO PACKAGE SLUG. ( ) ARE FOR MAX2233. ________________________________________________________________ Maxim Integrated Products 1 For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800. For small orders, phone 1-800-835-8769. MAX2232/MAX2233 General Description MAX2232/MAX2233 900MHz ISM-Band, 250mW Power Amplifiers with Analog or Digital Gain Control ABSOLUTE MAXIMUM RATINGS VCC to GND ...........................................................-0.3V to +6.5V SHDN, CTRL, D0, D1 to GND ....................-0.3V to (VCC +0.3V) IRFIN ....................................................................................10mA RFIN Power (50Ω AC-coupled source). .........................+10dBm Output Load VSWR. ................................................................6:1 Continuous Power Dissipation (TA = +70°C) 16-Pin PQSOP (derate 80mW/°C above +70°C) ................3W Operating Temperature Range ...........................-40°C to +85°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10sec) .............................+300°C 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 (VCC = +2.7V to +5.5V, VCTRL = +2.2V, V SHDN = VD0 = VD1 = +2V, TA = -40°C to +85°C. No input signal applied, unless otherwise noted. Typical values are at VCC = +3.6V and TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP 2.7 MAX UNITS 5.5 V Supply Voltage Range VCC Shutdown Supply Current ICC V SHDN = 0.6V, VD0 = VD1 = 0.6V Standby Supply Current ICC VCTRL ≤ 0.4V (MAX2232) Logic Input High VIH SHDN (MAX2232), D0, D1 (MAX2233) Logic Input Low VIL SHDN (MAX2232), D0, D1 (MAX2233) 0.6 V 0.4 V VCC ≤ 4.8V 0.2 4.8V < VCC ≤ 5.5V 7.5 20.3 VCTRL MAX2232 CTRL Input for Gain-Control Mode VCTRL MAX2232 0.6 IIH V SHDN = 2.0V (MAX2232), VD0 = VD1 = 2.0V (MAX2233) -1 IIL V SHDN = GND (MAX2232), VD0 = VD1 = GND (MAX2233) -1 VCTRL = GND CTRL Input Current 25 2.0 CTRL Input for Standby Mode Logic Input Current 10 µA mA V V 10 µA 1 -1.5 1 VCTRL = 2.2V 1.5 µA AC ELECTRICAL CHARACTERISTICS (MAX2232/MAX2233 Evaluation Kit, V CC = +3.6V, V CTRL = +2.2V, SHDN = V CC (MAX2232), D0 = D1 = V CC (MAX2233), PRFIN = 0dBm, ƒRFIN = 915MHz, TA = +25°C, unless otherwise noted.) PARAMETER SYMBOL Frequency Range ƒIN Power Gain GP CONDITIONS (Notes 1, 2) MIN 902 Output Power Variation Over Temperature Output Power, Medium-Power Mode 2 POUT ∆POUT POUT MAX UNITS 928 MHz 23.9 VCC = 4.8V Output Power TYP VCC = 3.6V (Note 1) dB 25.4 22.9 23.9 VCC = 3.0V 22.5 VCC = 2.7V 21.6 TA = TMIN to TMAX (Note 1) 1.9 D0 = GND, D1 = VCC (MAX2233 only) 15.8 _______________________________________________________________________________________ 24.9 3.2 dBm dB dBm 900MHz ISM-Band, 250mW Power Amplifiers with Analog or Digital Gain Control (MAX2232/MAX2233 Evaluation Kit, V CC = +3.6V, V CTRL = +2.2V, SHDN = V CC (MAX2232), D0 = D1 = V CC (MAX2233), PRFIN = 0dBm, ƒRFIN = 915MHz, TA = +25°C, unless otherwise noted.) PARAMETER SYMBOL Output Power, Low-Power Mode POUT D0 = VCC, D1 = GND (MAX2233 only) 6.5 dBm Gain-Control Range (Note 3) ∆GP 0.6V < VCTRL < 2.2V (MAX2232 only) 23.6 dB Power-Added Efficiency PAE 44 % Power-Added Efficiency at +21dBm Output Power PAE CTRL adjusted to give PRFOUT = +21dBm (MAX2232 only) 29 % Supply Current, Medium-Power Mode ICC D0 = GND, D1 = VCC (MAX2233 only) 78.5 mA Supply Current, Low-Power Mode ICC D0 = VCC, D1 = GND (MAX2233 only) 44.0 mA ZSOURCE = 50Ω (Note 1) 1.5:1 Input VSWR VSWR Input VSWR Change, Shutdown Mode (Notes 1, 4) ∆VSWR Input VSWR Change, Standby Mode (Notes 1, 4) ∆VSWR CONDITIONS MIN TYP MAX UNITS 1.4:1 MAX2232 only 1.2:1 SHDN = D0 = D1 = GND 52 CTRL = GND (MAX2232 only) 38 Maximum Nonharmonic Spurious Output Due to Load Mismatch VCC = +2.7V to +5.5V, 6:1 VSWR at any phase angle, PRFIN = +5dBm -60 dBc Maximum Output Load VSWR Without Damage (Note1) Any load phase angle, PRFIN = +5dBm, TA = TMIN to TMAX Harmonic Suppression (Note 5) 29 dBc Autoramping Rise Time CRAMP = 0.22µF (Notes 1, 6) (MAX2232 only) 0.9 ms Autoramping Fall Time CRAMP = 0.22µF (Notes 1, 7) (MAX2232 only) 3.2 ms Output Power Rise Time RAMP+ = RAMP- = unconnected (Note 6) 0.4 µs Off-Isolation dB 6:1 Thermal Shutdown Temperature TTH PRFIN = 0dBm, VCC = +3.6V 145 °C Thermal Shutdown Timeout Period tTH CTSET = 0.22µF (Note 8) 900 ms Guaranteed by design. Operation outside this range is possible, but not characterized. Gain is monotonic with VCTRL. Input VSWR relative to input impedance in operating mode. Harmonics measured on evaluation kit, which provides some harmonic attenuation in addition to the rejection provided by the IC. The combined suppression is specified. Note 6: Time measured from SHDN (MAX2232) low-to-high transition to when output power is within 1dB of final value. Includes effects of 1% tolerance capacitor. Note 7: Time measured from SHDN (MAX2232) high-to-low transition to when output power is -20dB of final value. Includes effects of 1% tolerance capacitors. Note 8: Time from die temperature dropping below Thermal Shutdown Temperature, TTH, to when the device turns itself back on. Note 1: Note 2: Note 3: Note 4: Note 5: _______________________________________________________________________________________ 3 MAX2232/MAX2233 AC ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (MAX2232/MAX2233 Evaluation Kit, VCC = +3.6V, CTRL = VCC, SHDN = D0 = D1 = VCC, PRFIN = 0dBm, fRFIN = 915MHz, TA = +25°C, unless otherwise noted.) MAX2232 STANDBY SUPPLY CURRENT vs. SUPPLY VOLTAGE TA = +85°C 1 0.1 TA = +25°C 20 15 10 TA = -40°C 5 0.001 4.0 4.5 5.0 5.5 2.5 3.0 SUPPLY VOLTAGE (V) 3.5 4.0 4.5 5.0 3.5 4.0 4.5 5.0 5.5 SUPPLY VOLTAGE (V) 30 OUTPUT POWER vs. FREQUENCY TA = +25°C MAX2232/33 toc05 30 OUTPUT POWER (dBm) 25 30 TA = +85°C 10 MAX2233 (D0 = D1 = 1), AND MAX2232 20 15 MAX2233 (D0 = 0, D1 = 1) TA = -40°C 25 OUTPUT POWER (dBm) MAX2232/33 toc04 POWER-ADDED EFFICIENCY (%) 3.0 MAX2232 OUTPUT POWER vs. GAIN CONTROL VOLTAGE TA = -40°C 20 TA = +85°C 2.5 SUPPLY VOLTAGE (V) 60 40 23 5.5 POWER-ADDED EFFICIENCY vs. SUPPLY VOLTAGE 50 24 20 0 3.5 TA = +25°C 25 21 TA = +25°C 3.0 26 22 TA = -40°C 2.5 TA = -40°C 27 MAX2232/33 toc06 0.01 TA = +85°C MAX2232/33 toc03 25 SUPPLY CURRENT (mA) 10 VSHDN = VCC VCTRL = GND RFIN = UNCONNECTED OUTPUT POWER vs. SUPPLY VOLTAGE 28 OUTPUT POWER (dBm) 30 MAX2232/33 toc01 SHUTDOWN SUPPLY CURRENT (µA) 100 MAX2232/33 toc02 SHUTDOWN SUPPLY CURRENT vs. SUPPLY VOLTAGE 20 TA = +25°C TA = +85°C 15 10 5 10 MAX2233 (D0 = 1, D1 = 0) 0 3.0 3.5 4.0 4.5 5.0 5.5 902 POUT TA = -40°C 23 TA = +25°C 915 VCTRL (V) 928 MAX2232 RFIN PORT VSWR vs. FREQUENCY OUTPUT POWER AND POWER-ADDED EFFICIENCY vs. INPUT POWER 28 0.6 0.8 1.0 1.2 1.4 1.6 .1.8 2.0 2.2 2.4 5 SUPPLY VOLTAGE (V) MAX2232/33 toc07 0 MAX2232 OUTPUT POWER vs. SHUTDOWN CONTROL MAX2232/33 toc10 2.0 85 MAX2232/33 toc08 2.5 SHUTDOWN MODE 1.8 70 STANDBY MODE 0 13 PAE TA = +25°C 8 55 40 VSWR TA = -40°C 18 1.6 NORMAL OPERATION 1.4 LINEAR SCALE 25 OUTPUT POWER 1.2 TA = +85°C 3 -20 -15 -10 -5 0 INPUT POWER (dBm) 4 5 10 3V SHUTDOWN TA = +85°C PAE (%) OUTPUT POWER (dBm) MAX2232/MAX2233 900MHz ISM-Band, 250mW Power Amplifiers with Analog or Digital Gain Control 10 15 1.0 902 915 FREQUENCY (MHz) 928 1ms/div CRAMP = 0.22µF _______________________________________________________________________________________ 900MHz ISM-Band, 250mW Power Amplifiers with Analog or Digital Gain Control PIN NAME FUNCTION MAX2232 MAX2233 1 1 RFIN RF Input Port. Requires external matching network and blocking capacitor. 2 2 GND Input Stage Ground. Connect directly to low-inductance ground plane. If vias are used, separate them from other GND pin vias. 3 — SHDN Shutdown Control Input. Drive SHDN low to place the device in shutdown mode. Drive high for normal operation. — 3 D1 4 — CTRL — 4 D0 Digital Gain/Shutdown Control Input. LSB of the 2-bit digital output power control. D0 and D1 set the output power to one of three discrete levels. To place the device in shutdown, drive D0 and D1 low (Table 2). 5, 6 5, 6 GND Second Stage Ground. Connect directly to low-inductance ground plane. If vias are used, separate them from other GND pin vias. 7 7 GND Output Stage Ground. Connect directly to low-inductance ground plane. If vias are used, separate them from other GND pin vias. 8 8 RFOUT 9 9, 13, 14 N.C. No Connection. Do not make a connection to this pin. 10 10 TSET Thermal Shutdown Timeout Capacitor Terminal. Connect a capacitor from TSET to ground to limit thermal cycling. 11 11 VCC Second Stage Supply Voltage. Bypass with appropriate capacitors to GND. 12 12 VCC Input Stage Supply Voltage. Bypass with appropriate capacitors to GND. 13 — RAMP- Negative Terminal of Output Power Ramp Capacitor. Connect capacitor, CRAMP, between RAMP+ and RAMP- to control the rise and fall time of the output power ramp. 14 — RAMP+ Positive Terminal of Output Power Ramp Capacitor. Connect capacitor, CRAMP, between RAMP+ and RAMP- to control the rise and fall time of the output power ramp. 15 15 GND Bias Circuitry Ground. Connect directly to low-inductance ground plane. If vias are used, separate them from other GND pin vias. 16 16 VCC Bias Circuitry Supply Voltage. Bypass with appropriate capacitors to GND. SLUG SLUG GND Output Stage Ground. Provides additional thermal conduction, as well as a low-inductance path to ground. Connect directly to low-inductance ground plane. Digital Gain/Shutdown Control Input. MSB of the 2-bit digital output power control. D0 and D1 set the output power to one of three discrete levels. To place the device in shutdown, drive D0 and D1 low (Table 2). Analog Gain-Control Input. Apply a voltage between 0.6V and 2.2V to vary the gain of the PA. Drive CTRL below 0.4V to place the device in standby mode. Drive CTRL above 2.2V to place the device in peak output power mode. Open-Collector, RF Output Port. Connect output matching network to this pin. _______________________________________________________________________________________ 5 MAX2232/MAX2233 Pin Description MAX2232/MAX2233 900MHz ISM-Band, 250mW Power Amplifiers with Analog or Digital Gain Control Detailed Description The MAX2232/MAX2233 are nonlinear power amplifiers (PAs) intended for constant envelope applications (FM, FSK, GMSK). The devices operate over the 902MHz to 928MHz frequency range and provide typically 250mW of output power and 44% efficiency from a single +2.7V to +5.5V supply. Both devices typically provide 24dB of gain, which is adjustable over a continuous 24dB range through an analog voltage on CTRL of the MAX2232 or in two 10dB steps through the 2-bit programmable gain inputs (D0, D1) on the MAX2233. A low-power shutdown mode on both devices reduces supply current to 0.2µA. All bias, gain control, and temperature-sensing circuitry is provided on-chip to save board space and reduce component count. The signal path includes a variable gain amplifier (VGA), an output driver, and an output power transistor. On-chip interstage matching networks are provided for optimal loading and power transfer. Internal bias circuitry responds to CTRL and SHDN of the MAX2232, or to the 2-bit gain/shutdown control DAC of the MAX2233, providing optimum biasing and efficiency as well as shutdown and ramp control functions. A unique temperature-sensing circuit protects the device from overheating by shutting down the PA until a safe temperature is resumed. The devices come in a 16-pin PQSOP package, which incorporates a slug on the bottom of the device to increase heat conduction and provide a low inductance path to ground. RF Input Stage (Variable Gain Amplifier) V CC for proper biasing, as well as a proper output matching network to ensure optimum output power. Connect the output matching network to RFOUT (pin 8). See the Typical Application Circuit for bias and matching components suitable for 900MHz operation. The ground of the output stage is connected to a metal slug on the bottom of the MAX2232/MAX2233’s 16-pin PQSOP package. The metal slug increases heat conduction and provides a low-inductance path to ground. Solder the metal slug to the PC-board ground plane. ___________________________MAX2232 Analog Gain Control and Power Management Shutdown Mode Drive the shutdown (SHDN) pin below 0.6V to place the MAX2232 in shutdown mode. The VGA, driver, and output transistor are off in shutdown mode and the supply current is typically reduced to 0.2µA. When SHDN is above 2.0V, the device is enabled. Standby Mode Drive SHDN above 2.0V and CTRL below 0.4V to place the MAX2232 in standby mode. In standby mode, the VGA remains biased while the driver and output transistor are disabled. Supply current is typically 20mA in standby mode. This mode allows the device to maintain a good input VSWR while maintaining 38dB of isolation. This is useful to users who drive the PA with a direct modulated VCO, where pulling of the VCO results from changes in the input VSWR. The input stage includes a variable gain amplifier (VGA) with 24dB gain-control range. With the appropriate matching network, the input VSWR is nominally 1.5:1 during operation and the change in VSWR is only 1.2:1, relative to normal operation. This stage remains active during standby mode (MAX2232) to provide a constant input impedance but is off during shutdown mode (MAX2232/MAX2233). AC-couple this port with a DC-blocking capacitor. Analog Gain Control The voltage applied to the gain-control (CTRL) pin varies the output power of the MAX2232 continuously over a 24dB range. An internal comparator holds the PA to a constant peak output power if VCTRL is above 2.2V. For VCTRL below 0.4V, the PA is in standby mode. CTRL presents a high input impedance, allowing the VCTRL voltage to be set with a resistor-divider or a voltage output DAC. RF Second Stage (Driver) The internal bias circuitry of the MAX2232 automatically ramps the output power of the PA down or up at a constant rate (in W/sec) when switched in or out of shutdown mode. The output power is ramped to the level set by VCTRL on the MAX2232. The output power rise and fall time ramp is set by placing a capacitor, CRAMP, between RAMP+ and RAMP-. This provides an easy means of avoiding spectral splatter and complying with transmit mask requirements, without using a separate controller. The output power rise and fall time is set by the value of CRAMP. The driver provides gain to overcome interstage matching losses and to produce a signal large enough to drive the output power transistor into saturation. The driver stage is off during standby (MAX2232) and shutdown (MAX2232/MAX2233) modes. RF Output Stage (Output Power Transistor) The output power transistor delivers +24dBm of output power from a single +3.6V supply. The transistor’s open-collector output requires a pull-up inductor to 6 Output Power Autoramping _______________________________________________________________________________________ 900MHz ISM-Band, 250mW Power Amplifiers with Analog or Digital Gain Control Digital Gain Control and Power Management The MAX2233 responds to logic-level signals at the device’s 2-bit DAC inputs, D0 and D1, placing the device in shutdown mode or into one of three discrete output power levels. See Table 2 for operating modes and output power levels. Setting D0 and D1 to a logiclevel low places the device in shutdown mode and reduces supply current to 0.2µA. The VGA, driver, and output stage are off in shutdown mode, while the input impedance is only slightly changed. Setting D0 and D1 to one of the other three modes adjusts the output power to one of three discrete levels in 10dB steps. Thermal Shutdown The MAX2232/MAX2233 feature a thermal shutdown mode that helps to protect the device from damage when the die temperature becomes excessive. If the temperature of the die exceeds the thermal shutdown temperature, TTH, the VGA is forced into a low-gain mode and output power is reduced to a minimum. After Table 1. MAX2232 Operating Modes MODE V SHDN VCTRL OUTPUT POWER (PRFIN = 0dBm, VCC = +3.6V) Shutdown Standby < 0.6V > 2.0V X ≤ 0.4V < -35dBm < -35dBm Variable Gain > 2.0V 0.6V ≤ VCTRL < 2.2V 0dBm to +24dBm Maximum Gain X = Don’t care > 2.0V > 2.2V +24 dBm the PA’s die temperature drops below TTH, the device remains in thermal shutdown mode for the thermal shutdown timeout period, tTH. A single capacitor, CTSET, from TSET to ground sets tTH. The thermal shutdown timeout period helps to limit device thermal cycling that results if the source of the excessive temperature is not removed. tTH is set by the value of CTSET. Applications Information Proper attention to voltage supply bypassing is essential for high-frequency RF circuit stability. Bypass VCC with 0.1µF, 10nF, and 100pF capacitors in parallel with each other to ground. Use separate vias to the ground plane for each of the bypass capacitors and minimize trace length to reduce inductance. Use separate vias to the ground plane for each ground pin. Use low-inductance ground connections. Decouple SHDN, CTRL, D0, and D1 with 0.1µF capacitors to ground to minimize noise on the internal bias cell. Use a series resistor (typically 100Ω) to further reduce coupling of high-frequency signals into the control pins. Table 2. MAX2233 Operating Modes Truth Table D1 D0 OUTPUT POWER (PRFIN = 0dBm, VCC = +3.6V) Shutdown 0 0 < -35dBm Low Power 0 1 +6.5dBm Medium Power 1 0 +15dBm High Power 1 1 +24dBm MODE Functional Diagrams VCC GND 16 15 RAMP+ RAMPSHDN VCC CTRL VCC RFIN VCC 16 GND 15 14 13 BIAS BIAS MAX2232 3 TEMP SENSOR 11 10 TSET 4 12 8 1 RFOUT D0 D1 VCC VCC RFIN VGA 2 GND DRIVER 5, 6 GND 4 3 TEMP SENSOR 2-BIT DAC 11 12 10 8 TSET RFOUT 1 VGA 7, SLUG GND MAX2233 2 GND DRIVER 5, 6 GND 7, SLUG GND _______________________________________________________________________________________ 7 MAX2232/MAX2233 ___________________________MAX2233 Typical Application Circuit 0.22µF 68pF 1 RFIN VCC RFIN VCC 16 100pF 15nH 2 3 100pF 4 100pF 5 GND MAX2232 MAX2233 GND SHDN (D1) RAMP+ (N.C.) CTRL (D0) RAMP(N.C.) GND VCC VCC GND 14 CRAMP 0.22µF 13 VCC 12 10nF GND TSET 10nF RFOUT 3.6pF N.C. RFOUT 0.1µF 10 CTSET 0.22µF 0.22µF 8 0.1µF VCC 11 100pF 7 0.1µF 15 100pF 6 10nF 9 2.55nH NOTES: ( ) APPLIES TO MAX2233. BACKSIDE SLUG MUST BE SOLDERED TO GROUNDPLANE. 27nH VCC 100pF 10nF 0.1µF Package Information PSSOPPS.EPS MAX2232/MAX2233 900MHz ISM-Band, 250mW Power Amplifiers with Analog or Digital Gain Control Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 1999 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.