Freescale Semiconductor MC13851 Quick Start

Freescale Semiconductor

Quick Start Guide

MC13851 Evaluation Board Quick Start —
2400 MHz
INTRODUCTION
This evaluation board design demonstrates one possible
design at 2.75 V that satisfies competing requirements for NF,
IP3, gain, return losses and current consumption. By
changing any of the requirements, the performance for a
particular parameter can be improved to meet a particular
spec requirement.
This circuit was designed to provide NF of 1.5 dB, S21 gain
> 15 dB using R1 = 1.2 kΩ and 1.5 kΩ.
Bias resistor R1 is used to adjust for the desired current
drain and IP3 performance.
Gain or NF can be improved with matching changes to meet
specific requirements.
Table 1. Evaluation Board Measurements
at P = --30 dBm)
in
Serial # R1 Mode
1 1.2k Active
1 1.2k Bypass
2 1.2k Active
2 1.2k Bypass
3 1.2k Active
3 1.2k Bypass
1 1.5k Active
1 1.5k Bypass
2 1.5k Active
2 1.5k Bypass
3 1.5k Active
3 1.5k Bypass
Table 2. S- -Parameters
(2400 MHz, V
Serial # R1
1 1.2k
1 1.2k
2 1.2k
2 1.2k
3 1.2k
3 1.2k
1 1.5k
1 1.5k
2 1.5k
2 1.5k
3 1.5k
3 1.5k
© Freescale Semiconductor, Inc., 2010. All rights reserved.
RF Engineering Bulletin
Freescale Semiconductor
(2400 MHz, V
CC
Input Output Power
Power Power Gain
(dBm) (dBm) (dB)
--30.00 --13.91 16.09
--30.00 --34.91 --4.91
--30.00 --13.76 16.24
--30.00 --35.09 --5.09
--30.00 --13.90 16.10
--30.00 --34.82 --4.82
--30.00 --14.09 15.91
--30.00 --34.88 --4.88
--30.00 --14.17 15.83
--30.00 --35.08 --5.08
--30.00 --14.18 15.82
--30.00 --34.85 --4.85
= 2.75 V)
CC
Mode
Active
Bypass
Active
Bypass
Active
Bypass
Active
Bypass
Active
Bypass
Active
Bypass
MC138512400QSG
Document Number:
Resistor R3 is used to de--Q output inductor L2 and adjust
gain and return losses. Lowering R3 lowers gain and improves
return losses.
The LNA is bias stabilized for variations in device and
temperature.
NOTE: Tables 1 and 2 list measured parameters on three
typical evaluation boards and are meant as a guide to the RF
performance possible for this application circuit. Variations in
matching component performance may result in variation in
evaluation board performance results.
= 2.75 V, Frequency Spacing = 200 kHz, Non--Linear Measurements
Output Input Output Ref
IP3 IP3
(dBm) (dBm)
17.59 1.5
20.29 25.2
16.99 0.75
20.31 25.4
17.80 1.7
20.48 25.3
19.01 3.1
20.82 25.7
17.33 1.5
20.22 25.3
17.92 2.1
20.15 25
S11 (dB) S21 (dB)
--11.96 15.76
--15.05 --5.03
--12.27 15.75
--14.27 --5.09
--13.12 15.68
--14.83 --4.96
--10.7 15.57
--14.7 --5.06
--10.4 15.43
--14.3 --5.14
--11.14 15.32
--14.77 --5.02
MC138512400QSG
Rev. 0, 11/2010
Input Ref
P P NF
1dB 1dB
(dBm) (dBm) (dB)
8.29 --7.8 1.51
— — 5.21 1.56n A
8.04 --8.2 1.5
— — 5.47 3.6 nA
8.20 --7.9 1.51
— — 5.08 7.6 nA
8.01 --7.9 1.5
— — 5 1.56 nA
7.83 --8.0 1.52
— — 5.29 3.6 nA
8.12 --7.7 1.52
— — 5.09 7.6 nA
S12 (dB) S22 (dB)
--23.6 --13.4
--5.3 --22.8
--23.8 --11.63
--5.4 --23.5
--23.5 --11.47
--5.19 --21.7
--23.7 --12.38
--5.4 --21.40
--23.2 --10.91
--5.44 --23.20
--23.1 --10.8
--5.26 --21.17
I
CC
(mA)
5.1
4.47
4.54
4.02
3.55
3.63
1