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19-1093; Rev 2; 1/98
MAX2430 Evaluation Kits
________________General Description
The MAX2430EVKIT-SO and MAX2430EVKIT-QSOP evaluation kits (EV kits) simplify evaluation of the MAX2430 silicon RF power amplifier. They enable testing of all MAX2430 functions over the 800MHz to 950MHz band, with no additional support circuitry and with minimal equipment. To evaluate the MAX2430 in the SO package (MAX2430ISE), order the MAX2430EVKIT-SO. To evaluate the MAX2430 in the PwrQSOP package, order the MAX2430EVKIT-QSOP. These are surface-mount packages.
____________________________Features
o Low-Cost, Silicon RF Power Amplifier o Delivers More than 125mW Output Power from +3.6V Supply o Single +3V to +5.5V Supply Range, Ideal for 3-Cell NiCd or 1-Cell Lithium-Ion Battery Operation o Output Matching Network is Tunable from 800MHz to 950MHz o TTL/CMOS-Compatible Shutdown Input o Easy Testing of All MAX2430 Features o Fully Assembled and Tested Surface-Mount Package
Evaluate: MAX2430
_______________Ordering Information
PART MAX2430EVKIT-PwrQSOP MAX2430EVKIT-SO TEMP. RANGE 0C to +70C 0C to +70C IC PACKAGE 16 PwrQSOP 16 Narrow SO
______________________________________________________________Component List
MAX2430EVKIT-SO
DESIGNATION QTY C1-C5 C6 5 1 DESCRIPTION 1nF, 10% ceramic chip capacitors (0805) 2.2nF, 10% ceramic chip capacitor (0805) 1F, 10V, 10% tantalum capacitor SMT AVX TAJA105K016 0pF to 6pF SMT trimmer capacitors Voltronics JR060 8nH, 10% spring inductors Coilcraft A03T 47nH, 20% inductor Coilcraft 0805CS-470XMBC 470, 5% resistor (0805) SMA connectors MAX2430ISE Supply connectors 3-pin header Shunt RC PIN, POUT U1 VCC, GND J1 None 1 2 1 2 1 1
MAX2430EVKIT-PwrQSOP
DESIGNATION QTY C1-C5 C6 5 1 DESCRIPTION 1nF, 10% ceramic chip capacitors (0603) 2.2nF, 10% ceramic chip capacitor (0603) 1F, 10V, 10% tantalum capacitor SMT AVX TAJA105K016 0pF to 6pF SMT trimmer capacitors Voltronics JR060 8nH, 10% spring inductor Coilcraft A03T 12nH, 10% spring inductor Coilcraft A04T 47nH, 20% inductor Coilcraft 0805CS-470XMBC 470, 5% resistor (0603) SMA connectors MAX2430IEE Supply connectors 3-pin header Shunt
C7
1
C7
1
CO, CSH L1, L2 LC RC PIN, POUT U1 VCC, GND J1 None
2 2 1 1 2 1 2 1 1
CO, CSH L1 L2 LC
2 1 1 1
______________Component Suppliers
SUPPLIER AVX Coilcraft Sprague Voltronics PHONE (803) 946-0690 (847) 639-6400 (603) 224-1961 (201) 586-8585 FAX (803) 626-3123 (847) 639-1469 (603) 224-1430 (201) 586-3404
________________________________________________________________ Maxim Integrated Products
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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.
MAX2430 Evaluation Kits Evaluate: MAX2430
_________________________Quick Start
The MAX2430 EV kits are fully assembled and factory tested. All measurements described below use a 900MHz test frequency. Do not turn on the power until all connections are made. the input power up or down in 0.1dB steps to get the equivalent output power equal to 20dBm at the POUT port. The power gain (GP = POUT - PIN) should be greater than 30dB. If you cannot achieve 20dBm output power, verify that the supply voltage between the VCC and GND pads on the EV kit is 3.00V. This ensures that the supply connection wire and current-meter shunt losses are not causing excessive supply voltage drops. Also, make sure the output stage matching network has been properly tuned for the center frequency of interest, according to the CO and CSH trim-capacitor tuning procedure found in the Adjustments and Control section. Disable the MAX2430 by moving the J1 shunt to pins 2 and 3. With the part disabled and RF power still applied to the RF input, you can measure the offstate feedthrough of the MAX2430. Adjust your spectrum analyzer to display the amount of 900MHz leakage power that exists at the POUT port. The isolation should be approximately 50dB, so with an input power of -12dBm, the output power should measure approximately -62dBm. Enable the MAX2430 again by moving the J1 shunt to pins 1 and 2. Note that the output power is again around 20dBm. Set the spectrum analyzer to display the 1800MHz 2nd harmonic frequency. The measured power should be typically 26dB down from the fundamental power at 900MHz. The 3rd harmonic power at 2700MHz should be typically 40dB down. The threeelement output stage matching circuitry provides some rejection of the harmonic products. Set the spectrum analyzer to measure the 900MHz fundamental power. Adjust VCC from 3V up to 5.5V. Note that the output power has risen approximately 2dBm (up to 22dBm) and that the power gain has increased by 2dB.
Test Equipment Required
* Signal-Source Sine-Wave Generator with range up to 1000MHz (example: HP8656B) * Spectrum Analyzer with range up to 4GHz (example: TEK2755AP) * +3V to +5.5V, 400mA adjustable output power supply * Current meter that can display up to 400mA
2)
Connections and Signal Conditions
1) Connect an SMA cable from the RF signal source to the PIN input on the EV kit. Ensure that the RF powersource input power is off or set below -50dBm. 2) Connect an SMA cable from the spectrum analyzer to the POUT connector on the EV kit. Note that if the front end of the spectrum analyzer can not handle more than 20dBm of input power, you must place an appropriate attenuator between the POUT connector and the spectrum analyzer to prevent damage. 3) Connect the 3V power supply through a current meter to the appropriate VCC and GND terminals on the EV kit, and apply power. 4) Position the J1 shunt across pins 1 and 2 to enable the MAX2430 (SHDN = high). Note that the normal bias current drawn by the MAX2430 EV kit should be approximately 30mA to 60mA over the 3V to 5.5V supply range when no RF input power is applied. 5) Set the input power to -20dBm and the frequency to 900MHz on the signal source. 6) Set the spectrum analyzer's dynamic range and frequency range for an appropriate setting to view the 900MHz output. 7) Tune the output stage matching network for maximum output power at 900MHz. See the Adjustments and Control section for the CO and CSH trim-capacitor tuning procedure
3)
4)
5)
Adjustments and Control
CO and CSH The quickest method for tuning the output is to apply -20dBm of input power at the desired frequency, then adjust CO and CSH until the output power is maximized as read from a spectrum analyzer or power-meter display. Only one value of CO and CSH is correct for a given frequency. For best results, use a nonconductive adjustment tool.
CO and CSH are surface-mount, 0pF to 6pF trim capacitors used to tune the output transistor matching
_______________Detailed Description
Analysis
1) Set the RF source power to -13dBm. At 900MHz, the spectrum analyzer should display a power level near 20dBm (of course, if you have used an attenuator, adjust your reading accordingly). If necessary, adjust
2
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MAX2430 Evaluation Kits
network to 50. This ensures maximum power transfer and good output VSWR at any selected narrow-band frequency range of interest between 800MHz and 950MHz. The open-collector output transistor (RFOUT pin) should see approximately a 15 internal load impedance to achieve maximum power gain with the best efficiency. The internal package inductance (5nH), L1 (8nH), series capacitor C O, and shunt capacitor CSH form a 15 to 50 tuneable matching network. Resistor RC enhances stability under load mismatch conditions and does not affect normal operation of the circuit. The 47nH supply choke (labeled LC) provides DC bias.
BIAS Pin section of the MAX2430 data sheet for more information on output power control.
Evaluate: MAX2430
Layout Considerations
The evaluation board can serve as a guide for board layout. Grounding is critical for the proper operation and stability of the MAX2430. The following considerations were taken into account on the evaluation board. C1, C2, and C3 should be small surface-mount capacitors, placed directly from each effective VCC terminal to the ground plane. Make connections short (not through vias or long traces). C5 and C6 should be surface-mount capacitors, located as close to the MAX2430 as possible for best results. C2 should be next to L2. C3 should be next to LC. LC should be perpendicular to L1, and L1 perpendicular to L2 to ensure minimal coupling. The evaluation board has four layers made from FR4 (R = 4.0 to 4.6) with 1oz. copper. The first two layers (signal and ground planes) are 14 mils apart, which provides a 50 characteristic impedance from 25mil-wide traces. These trace widths are used for PIN and POUT to maintain a 50 environment out to the SMA connectors. The third layer is used for the V CC supply plane. The fourth layer is used for the SHDN pin jumper connections and BIAS pin signal routing. The ground metal, connected with vias on the first and second layers, acts as a heatsink for the MAX2430, reducing internal operating temperatures. Note that all ground and V CC plane is removed under matching components (L1, L2, LC, RC, CO, CSH) to minimize parasitic capacitance. The MAX2430EVKIT-QSOP includes two large holes under the MAX2430 to aid in attachment and removal of the part. These holes are not necessary for proper circuit operation.
Shutdown Control The SHDN pin is TTL/CMOS compatible and is used to enable (or disable) the MAX2430. Table 1 lists the options available for the shutdown control jumper, J1. To use an external control signal, remove the shunt on J1 completely, and connect the external signal to the pad marked SHDN. The external control signal should not exceed VCC. Supply current in the disabled mode
Table 1. Jumper J1 Functions
SHUNT LOCATION 1&2 2&3 SHDN PIN Connected to VCC Connected to GND MAX2430 STATUS Enabled Disabled
is typically less than 1A.
BIAS Pin The BIAS pin regulates the ramp-up and ramp-down times of the output RF envelope. It can also be driven externally to control the output power over a 15dB range. The rampup/down slope is set by a capacitor connected from the BIAS pin to ground. The EV kit comes with a 2.2nF capacitor (C6), which yields an RF envelope ramp-up/down time of approximately 10s. The BIAS pad on the EV kit allows the user to manipulate the MAX2430 BIAS pin. Refer to the
Operation Outside the 800MHz to 950MHz Frequency Band
With minor modifications to the MAX2430 EV kit matching network components, the operating frequency can be tuned to frequencies outside the specified band. Refer to the Applications Information section of the MAX2430 data sheet for more information.
_______________________________________________________________________________________
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MAX2430 Evaluation Kits Evaluate: MAX2430
VCC
C7 C4 1F 1nF 10V 123 J1 2
C1 1nF
C2 1nF
L2* 8 VCC2 10 BIAS
C6 2.2nF
BIAS
* L2 = 8nH FOR NARROW SO PACKAGE (MAX2430ISE) L2 = 12nH FOR PwrQSOP PACKAGE (MAX2430IEE) VCC
SHDN
7 VCC1 MASTER BIAS
C3 1nF OUTPUT BIAS 5nH LC 47nH 9 RFOUT ~15 RC 470 L1 8nH CO 0pF to 6pF CSH 0pF to 6pF GND4 11, 12, 13, 14 CO AND CSH TUNED FOR MAXIMUM POWER OUTPUT AT THE DESIRED FREQUENCY BETWEEN 800MHz AND 950MHz. SMA POUT
SHDN 6 GND1
MAX2430
C5 SMA 1nF PIN 50 GND 4 RFIN DRIVER GAIN GND2 3, 5 GND3 1, 15, 16
50
Figure 1. MAX2430 EV Kit Schematic
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Figure 2. MAX2430 EVKIT-SO Component Placement Guide-- Component Side
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Figure 3. MAX2430 EVKIT-SO PC Board Layout-- Component Side
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MAX2430 Evaluation Kits Evaluate: MAX2430
1.0"
Figure 4. MAX2430 EVKIT-SO PC Board Layout-- Solder Side
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Figure 5. MAX2430 EVKIT-SO PC Board Layout--Ground Plane
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Figure 6. MAX2430 EV Kit-PwrQSOP Component Placement Guide--Component Side
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Figure 7. MAX2430 EV Kit-PwrQSOP PC Board Layout-- Solder Side
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MAX2430 Evaluation Kits Evaluate: MAX2430
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Figure 8. MAX2430 EV Kit-PwrQSOP PC Board Layout-- Component Side
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Figure 9. MAX2430 EV Kit-PwrQSOP PC Board Layout-- Ground Plane
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Figure 10. MAX2430 EV Kit-PwrQSOP PC Board Layout-- Power Plane
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.
6 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 (c) 1998 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

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