AN0023 Application Note for CHT4690-QAG and CHT4690-99F Single control supply configuration GaAs Monolithic Packaged Microwave IC This note gives general recommendations for implementing and using the CHT4690 and CHT4690-QAG, in terms of control voltage. CHT4690-99F and CHT4690-QAG use two supply voltages, one for 1st stage, and the other for 2nd stage. Both can be operated from -5V to 0V. As described in the data-sheet, biasing voltage should be applied as following to obtain the best performances in linearity (dual control): - 1st stage attenuation control with V1 from –5V to 0V, with V2 fixed at -5V 2nd stage attenuation control with V2 from –5V to 0V, with V1 fixed at 0V Nevertheless, it is possible to use a common control, and this is the subject of this application note, driving with the same supply both V1 & V2. There is no impact on the dynamic range: the minimum and maximum attenuation levels remain the same. The drawback will be the in-between linearity behaviour. As a matter of fact, the 1st stage will not protect the 2nd stage in terms of power as it does with the dual control. The linearity is then reduced. The worst case in term of linearity is obtained for V1= V2 = -3.5V with an input power at -1dB minimum of 20dBm instead of 24dBm for the standard polarisation (configuration V1 = -3.5V / V2 = -5V). Ref. : AN0023_9092_02 Apr 09 1/6 Subject to change without notice United Monolithic Semiconductors S.A.S. Route Départementale 128 - BP46 - 91401 Orsay Cedex France Tel.: +33 (0)1 69 33 03 08 - Fax: +33 (0)1 69 33 03 09 AN0023 1. Single control supply for CHT4690-QAG (QFN packaged product) The electrical characteristics of CHT4690-QAG (at 25°C) for both configurations are given in the table below. Electrical Characteristics Temp. = 25°C CHT4690-QAG Symbol Fin Min Att. Dual control Parameter Min Typ Input frequency range VSWR out Pin1dB C/I3 V1,V2 30 Max Unit 5 30 GHz |S21| (V1=-5V;V2=-5V) (5 to 10GHz) -2 -3 -2 -3 dB |S21| (V1=-5V;V2=-5V) (11 to 24GHz) -4 -5.5 -4 -5.5 dB |S21| (V1=-5V;V2=-5V) (25 to 30GHz) -6 -7.5 -6 -7.5 dB |S21| (V1=0V;V2=0V) (11 to 30GHz) in Max Min Typ 5 Max Att. |S21| (V1=0V;V2=0V) (5 to 10GHz) VSWR Single control -22 -24 -22 -24 dB -28 -35 -28 -35 dB Input VSWR (any attenuation) 2.0:1 2.0:1 2.5:1 2.5:1 (5 to 26GHz) Output VSWR (any attenuation) (6 to 26GHz) Input 1dB compression point (any attenuation) (5 to 25GHz) 24 25 19 20 dBm C/I3 @ Pin/tone=12dBm (any attenuation) (to 26GHz) 36 40 28 32 dB Voltage control range -5 0 V1 = -3.5V V2 = -5V Worst case in terms of linearity -5 0 V V1 = -3.5V V2 = -3.5V These values are representative of on board measurements as defined on the drawing 96272 (see paragraph "Proposed assembly board" of the data-sheet of CHT4690-QAG). Ref. : AN0023_9092_02 Apr 09 2/6 Subject to change without notice United Monolithic Semiconductors S.A.S. Route Départementale 128 - BP46 - 91401 Orsay Cedex France Tel.: +33 (0)1 69 33 03 08 - Fax: +33 (0)1 69 33 03 09 AN0023 Typical Results with single control supply Temp. = +25°C Measurements in the package access, using the proposed land pattern & board 96272, as defined in the CHT4690-QAG data-sheet. CHT4690-QAG: attenuation versus frequency V1 = V2 = -5V to 0V Figure 1 : Attenuation as a function of frequency Ref. AN0023_9092_02 Apr 09 3/6 Subject to change without notice United Monolithic Semiconductors S.A.S. Route Départementale 128 - BP46 - 91401 Orsay Cedex France Tel.: +33 (0)1 69 33 03 08 - Fax: +33 (0)1 69 33 03 09 AN0023 CHT4690-QAG: attenuation versus input power @ 5GHz V1 = V2 = -5V to 0V CHT4690-QAG: attenuation versus input power @ 15GHz V1 = V2 = -5V to 0V Ref. : AN0023_9092_02 Apr 09 4/6 Subject to change without notice United Monolithic Semiconductors S.A.S. Route Départementale 128 - BP46 - 91401 Orsay Cedex France Tel.: +33 (0)1 69 33 03 08 - Fax: +33 (0)1 69 33 03 09 AN0023 CHT4690-QAG: input IP3 versus input power V1 = V2 = -3.5V (worst case area for the linearity) 33 31 IIP3 (dBm) 29 27 5GHz 10GHz 25 15GHz 20GHz 23 21 19 0 2 4 6 8 10 12 14 16 18 Pin (dBm) single tone CHT4690-QAG: C/I3 versus input power V1 = V2 = -3.5V (worst case area for the linearity) V1=-3,5V / V2=-3,5V 45 5GHz 10GHz 15GHz 20GHz 40 CI3 (dBm) 35 30 25 20 15 0 2 4 6 8 10 12 14 16 18 Pin (dBm) single tone Ref. AN0023_9092_02 Apr 09 5/6 Subject to change without notice United Monolithic Semiconductors S.A.S. Route Départementale 128 - BP46 - 91401 Orsay Cedex France Tel.: +33 (0)1 69 33 03 08 - Fax: +33 (0)1 69 33 03 09 AN0023 2. Single power supply for CHT4690-99F (die product) The electrical characteristics of the die version can be deduced from the packaged product measurements. Electrical Characteristics Temp. = 25°C CHT4690-99F Symbol Fin Min Att. Max Att. VSWR in VSWR out Pin1dB C/I3 V1,V2 Dual power supply Parameter Min Typ Input frequency range 5 Max 30 Single power supply Min Typ 5 Max Unit 30 GHz |S21| (V1=-5V;V2=-5V) (5 to 12GHz) -2.5 -3 -2.5 -3 dB |S21| (V1=-5V;V2=-5V) (13 to 30GHz) -6.5 -7.5 -6.5 -7.5 dB |S21| (V1=0V;V2=0V) (5 to 12GHz) -22 -25 -22 -25 dB |S21| (V1=0V;V2=0V) (13 to 30GHz) -27 -34 -27 -34 dB Input VSWR (any attenuation) 2.3:1 2.3:1 2.5:1 2.5:1 (5 to 30GHz) Output VSWR (any attenuation) (8 to 30GHz) Input 1dB compression point (any attenuation) (5 to 20GHz) 24 25 19 20 dBm C/I3 @ Pin/tone=12dBm (any attenuation) (up to 26GHz) 36 40 28 32 dB Voltage control range -5 0 V1 = -3.5V V2 = -5V Worst case in terms of linearity -5 0 V V1 = -3.5V V2 = -3.5V Contacts: Web site: email: Phone: www.ums-gaas.com [email protected] 33 (1) 69 33 02 26 (France) +1 973 812 2139 (USA) +86 21 6103 1635 (China) Information furnished is believed to be accurate and reliable. However United Monolithic Semiconductors S.A.S. assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of United Monolithic Semiconductors S.A.S.. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. United Monolithic Semiconductors S.A.S. products are not authorised for use as critical components in life support devices or systems without express written approval from United Monolithic Semiconductors S.A.S. Ref. : AN0023_9092_02 Apr 09 6/6 Subject to change without notice United Monolithic Semiconductors S.A.S. Route Départementale 128 - BP46 - 91401 Orsay Cedex France Tel.: +33 (0)1 69 33 03 08 - Fax: +33 (0)1 69 33 03 09