• LOW NOISE FIGURE: NFmin = 1.05dB
@ 1.8GHz, 5mA, 2V
• COMPRESSION P1dB = 12.5dBm
@ 1.8GHz, 20mA, 2V
• ULTRA MINIATURE SOT343 PACKAGE
START420
NPN Silicon RF Transistor
SOT343 (SC70)
DESCRIPTION
ORDER CODE
START420TR
BRANDING
420
The START420 is a member of the START family
that provide market with the state of the art of RF
silicon process. Manufacturated in the third
generation of ST propri etary bipolar process, it
offers the best mix of gain and NF for given
breakdown voltage(BVceo).
It reaches performance level only achieved with
GaAs products before.
APPLICATIONS
• LNA FOR GSM/DCS, DECT, PDC, PCS,
PCN
• PREDRIVER FOR DECT
• GENERAL PURPOSE 500MHz-5GHz
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter Value Unit
V
ceo
V
cbo
V
ebo
I
c
I
b
P
tot
T
stg
T
j
Collector emitter voltage 4.5 V
Collector base voltage 15 V
Emitter base voltage 1.5 V
Collector current 40 mA
Base current 4 mA
Total dissipation, Ts = 101
Storage temperature -65 to 150
Max. operating junction temperature 150
180 mW
o
C
o
C
ABSOLUTE MAXIMUM RATINGS
R
thjs
Thermal Resistance Junction soldering point 270
o
C/W
1/7July, 3 2002
START420
ELECTRICAL CHARACTERISTICS (Tj=25 oC,unless otherwise specified)
Symbol Parameter Test Conditions Min. Typ. Max. Unit
I
cbo
I
ebo
Hfe DC current gain Ic = 20mA, Vce = 3V 100 150
NFmin Minimim noise figure
Ga NFmin associated gain Ic = 5mA, Vce = 2V, f = 1.8GHz 16 dB
|S21|
Gms
P
-1dB
OIP3
Note(1) : Gm s = | S21 / S12 |
PINOUT
Collector cutoff current Vcb = 5V, Ie = 0A 150 nA
Emitter-base cutoff
current
2
(1)
Insertion power gain Ic = 20mA, Vce = 2V, f = 1.8GHz 19.5 dB
Maximum stable gain Ic = 20mA, Vce = 2V, f = 1.8GHz 22.6 dB
1dB compression point Ic = 20mA,Vce = 2V, f = 1.8GHz 12.5 dBm
Ouput third order
intercept point
4
3
Top vie
12
SOT343
Veb = 1.5V, Ic = 0A 15 µA
Ic = 5mA, Vce = 2V, f = 1.8GHz,
Ic = 20mA,Vce = 2V, f = 1.8GHz 23 dBm
Z
s
= Zsopt
1.05 dB
PIN CONNECTION
Pin No. Description
1BASE
3 COLLECTOR
2,4 EMITTER
2/7
SPICE PARAMETERS (Gummel-Poon Model, Berkley-SPICE 2G.6 Syntax)
TRANSISTOR CHIP DAT A
Symbol Value Symbol Value Symbol Value
TMEAS 27.0 FC 0.66 XJBC 0.53
IS 1.00E-16 EG 1.12 XTI 3.76
ISE 1.58E-11 NF 1 BF 280
NR 1 NE 3.1 VAF 70
ISC 1.55E-15 BR 9.52 VAR 2.3
o
IKF
TR 7E-10 PTF 32.0 VTF 27.9
XTF 9.84 ITF 0.498 MJE 0.497
RB 12.86 RBM 5 MJC 0.292
RC 3.7 RE 0.42 MJS 0.245
CJE 421E-15 VJE 1.03 IKR 8.32E-3
CJC 160E-15 VJC 0.6 XTB -0.54
CJS 112E-15 VJS 0.4
{0.217*((T(
300.15)^(-1.63)}
C)+273.15)/
NC 1.495 TF 3.0E-12
PACKAGE EQUIVALENT CIRCUIT
C2
C=66 fF
START420
B
L4
L=0.6 nH
. .
B’ C’
L3 L5 L6
L=0.35 nH
C1
Transistor
Chip
E’
L=0.1 nH
L1
.
L=0.05 nHL2
.
E
L=0.3 nH L=0.6 nH
C3
C=334 fFC=436 fF
. .
C
In order to avoid high complexity of the package equivalent circuit, the two emitter leads of SOT-343
package are combined in one electrical connection.
FOR MORE ACCURACY SIMULATION IN SATURATION REGION :
Adding the 5 Spice parameters showed in Table A and using ST Spice Library (available on request) you
can achieve a more a ccuracy simulation in the saturation region. S T Spice library is compatible with
following simulators: ELDO MENTOR (any version), SPECTRE CADENCE (any version), ADS (version
2001 only).
Table A (Spice Parameters extracted in saturation region)
RW Vjj ENP VRP RP
1.173 0.8 2.085 {4.12*((TEMPER+273.15)/300.15)^(0.303)} 1.00E-6
3/7