Zetex ZNBG3115Q16, ZNBG3115Q20, ZNBG3116Q16, ZNBG3116Q20 Datasheet
FET BIAS CONTROLLER WITH POLARISATION
SWITCH AND TONE DETECTION
ISSUE 1 - JUNE 2001
DEVICE DESCRIPTION
The ZNBG series of devices are designed to meet the
bias requirements of GaAs and HEMT FETs
commonly used in satellite receiver LNBs, PMR,
cellular telephones etc. with a minimum of external
components.
With the addition of two capacitors and a resistor the
devices provide drain voltage andcurrentcontrolfor
three external grounded source FETs, generating
the regulated negative rail required for FET gate
biasing whilst operating from a single supply. This
negative bias, at -2.8 volts, can also be used to
supply other external circuits.
The ZNBG3115/16 includes bias circuits to drive up
to three external FETs. A control input to the device
selects either one of two FETs as operational, the
third FET is permanently active. This feature is
normally used as an LNB polarisation switch. Also
specific to Universal LNB applications is the 22kHz
tone detection and logic output feature which is
used to enable high and low band frequency
switching.
The ZNBG3115/16 has been designed to cope with
DiSEqC™ ready set top boxes and rejects all
transients from channel switching.
Drain current setting of the ZNBG3115/16 is user
selectable over the range 0 to 15mA, this is achieved
with addition of a single resistor. The series also offers
the choice of drain voltage to be set for the FETs, the
3115 gives 2.2voltsdrainwhilstthe3116gives2volts.
These devices are unconditionally stable over the full
working temperature with the FETs in place, subject to
the inclusion of the recommended gate and drain
capacitors. These ensure RF stability and minimal
injected noise.
It is possible to use less than the devices full
complement of FETbiascontrols, unused drain andgate
connections can be left open circuit without affecting
operation of the remaining bias circuits.
To protect the external FETs the circuits have been
designed to ensure that, under any conditionsincluding
power up/down transients, the gate drive from the bias
circuits cannot exceed the range -3.5V to 1V.
Additionally each stage has its own individual current
limiter. Furthermore if the negative rail experiences a
fault condition, such as overload or short circuit, the
drain supply to the FETs will shut down avoiding
excessive current flow.
The ZNBG3115/16 are available in QSOP16and QSOP20
for the minimum in device size. Device operating
temperature is -40 to 80°C to suit a wide range of
environmental conditions.
ZNBG3115
ZNBG3116
FEATURES
Provides bias for GaAs and HEMT FETs
•
Drives up to three FETs
•
Dynamic FET protection
•
Drain current set by external resistor
•
Regulated negative rail generator requires only
•
2 external capacitors
Choice in drain voltage
•
Wide supply voltage range
•
Polarisation switch for LNBs
•
22kHz tone detection for band switching
•
Tone detector ignores unwanted signals
•
Support fr MIMIC, FET and Bipolar local
•
oscillator devices
Compliant with ASTRA control specifications
•
QSOP 16 and 20 surface mount packages
•
ISSUE 1 - JUNE 2001
APPLICATIONS
Satellite receiver LNBs
•
Private mobile radio (PMR)
•
Cellular telephones
•
1
ZNBG3115
ZNBG3116
ABSOLUTE MAXIMUM RATINGS
Supply Voltage -0.6V to 12V
Supply Current 100mA
Input Voltage (V
Drain Current (per FET) 0 to 15mA
(set by R
CAL
) 25V Continuous
POL
)
Operating Temperature -40 to 80°C
Storage Temperature -50 to 85°C
ELECTRICAL CHARACTERISTICS. TEST CONDITIONS
(Unless otherwise stated):T
SYMBOL PARAMETER CONDITIONS
V
CC
I
CC
V
SUB
E
ND
E
NG
f
O
Supply Voltage 5 10 V
Supply Current ID1=ID2(or I
Substrate Voltage (Internally generated) I
Output Noise
Drain Voltage
Gate Voltage
Oscillator Frequency 180 330 800 kHz
= 25°C,V
amb
I
=0, ID2(or I
D1
I
=0,ID1(or I
D2
I
and ID3=0, ILB=10mA
D1
I
and ID3=0, IHB=10mA
D1
C
=4.7nF, CD=10nF
G
C
=4.7nF, CD=10nF
G
Power Dissipation (T
QSOP16 500mW
QSOP20 500mW
=5V,I
CC
D12
D12
D12
=10mA (R
D
)=ID3=0
)=ID3=10mA, V
)=ID3=10mA, V
CSUB
I
CSUB
POL
=15.5V
POL
=0
=-200µA
CAL
=14V
= 25°C)
amb
=33k )
LIMITS
MIN. TYP. MAX.
8.5
28
28
18
18
-3.05 -2.8 -2.55
15
35
35
25
25
-2.4VV
0.02
0.005
UNITS
mA
mA
mA
mA
mA
Vpkpk
Vpkpk
2
ISSUE 1 - JUNE 2001
ZNBG3115
ZNBG3116
SYMBOL PARAMETER CONDITIONS
GATE CHARACTERISTICS
I
GO
V
G1O
V
G1L
V
G1H
V
G2O
V
G2L
V
G2H
V
G3L
V
G3H
Output Current Range -30 2000
V
I
Dx
POL
(mA) (V) ( A)
Output Voltage
Gate 1 Off
Low
High
I
D1
I
D1
I
D1
=0 V
=12 V
=8 V
POL
POL
POL
Output Voltage
Gate 2 Off
Low
High
I
D2
I
D2
I
D2
=0 V
=12 V
=8 V
POL
POL
POL
Output Voltage
Gate 3 Low
High
I
=12 I
D3
I
=8 I
D3
DRAIN CHARACTERISTICS
I
D
I
Drng
I
I
V
V
V
⌬V
⌬V
I
L1
I
L2
DV
DV
D1
D2
D3
DV
DT
Current 8 10 12 mA
Current range Set by R
cal
Current Change
with V
with T
CC
j
VCC=5to10V
T
=-40 to +80°C
j
Drain 1 Voltage: High
ZNBG3115
ZNBG3116
I
=10mA, V
D1
I
=10mA, V
D1
Drain 2 Voltage: High
ZNBG3115
ZNBG3116
I
=10mA, V
D2
I
=10mA, V
D2
Drain 3 Voltage: High
ZNBG3115
ZNBG3116
I
=10mA, V
D3
I
=10mA, V
D3
Voltage Change
with V
with T
CC
j
VCC=5to10V
T
=-40 to +80°C
j
Leakage Current
Drain 1 †
Drain 2 †
V
D1
V
D2
=0.5V, V
=0.5V, V
=14 I
=15.5 I
=15.5 I
=15.5 I
=14 I
=14 I
=15.5V
POL
=15.5V
POL
=14V
POL
=14V
POL
=15.5V
POL
=15.5V
POL
=14V
POL
=15.5V
POL
I
GOx
GO1
GO1
GO1
GO2
GO2
GO2
GO3
GO3
=-10
=-10
=0
=-10
=-10
=0
=-10
=0
LIMITS
UNITS
MIN. TYP. MAX.
A
-2.5
-2.5
0.4
-2.5
-2.5
0.4
-3.0
0.4
-2.25
-2.25
0.75
-2.25
-2.25
0.75
-2.75
0.75
-2.0
-2.0
1.0
-2.0
-2.0
1.0
-2.5
1.0
V
V
V
V
V
V
V
V
015mA
2.0
1.8
2.0
1.8
2.0
1.8
0.5
0.05
2.2
2.0
2.2
2.0
2.2
2.0
0.5
50
2.4
2.2
2.4
2.2
2.4
2.2
10
10
%/V
%/°C
V
V
V
V
V
V
%/V
ppm
A
A
†QSOP20 only
ISSUE 1 - JUNE 2001
3
ZNBG3115
ZNBG3116
SYMBOL PARAMETER CONDITIONS
MIN. TYP. MAX.
TONE DETECTION CHARACTERISTICS
V
OUT
F
inz
AG Amplifier Gain V
FV
T
V
LOV
I
LOV
V
LBL
V
LBH
V
HBL
V
HBH
Filter Amplifier
Bias Voltage
5
Input Impedance V
V Threshold
Output Stage
L
Volt. Range
OV
5
6
LOVBias Current V
LBOutput Low V
LBOutput High V
HBOutput Low V
HBOutput High V
I
=0 1.75 1.95 2.15 V
fin
=100mV p/p 150
FIN
=100mV p/p 30 V/mA
FIN
100 170 350 mV p/p
IL=50mA(LBor HB) -0.5 VCC-1.8 V
=0 0.02 0.15 1.0
LOV
=0 IL=0 Enabled
LOV
Rlb-Csub=1MΩ
V
=3V IL=0mA Enabled
LOV
6
-3.05 -2.80 -2.55 V
6
-0.01 0 0.1 V
Rlb-Csub=1MΩ
=0 IL=10mA Disabled
LOV
V
=3V IL=50mA Disabled
LOV
=0 IL=0 Disabled
LOV
Rhb-Csub=1MΩ
V
=3V IL=0 Disabled
LOV
Rhb-Gnd=1MΩ
=0 IL=10mA Enabled
LOV
V
=3V IL=50mA Enabled
LOV
6
6
6
-0.025
2.903.0
-3.05 -2.80 -2.55 V
6
-0.01 0 0.1
6
6
-0.025
2.903.0
POLARITY SWITCH CHARACTERISTICS
I
POL
V
TPOL
T
SPOL
NOTES:
1. Thenegativebias voltages specified aregenerated on-chip using aninternal oscillator. Two externalcapacitors, C
purpose.
2. The characteristics are measured using an external reference resistor R
3. Noise voltage is not measured in production.
4. Noise voltage measurementis made with FETsand gate and draincapacitors in place onall outputs. C
ground, C
5 . These parameters are linearly relatedto V
6. These parameters are measured using Test Circuit 1
Input Current
Threshold Voltage
Switching Speed
, 10nF, are connected between drain outputs and ground.
D
=25V (Applied via R
V
POL
=25V (Applied via R
V
POL
=25V (Applied via R
V
POL
CC
=2kΩ)
POL
=2kΩ)
POL
=2kΩ)
POL
of value 33k wired from pins R
CAL
10 25 40
14 14.75 15.5 V
CAL
, 4.7nF, are connectedbetween gate outputs and
G
LIMITS
and C
NB
to ground.
UNITS
Ω
µA
0.025
3.1
V
V
V
V
0.025
3.1
V
V
µA
100 ms
, of47nFare required for this
SUB
4
ISSUE 1 - JUNE 2001
TEST CIRCUIT 1
ZNBG3115
ZNBG3116
Note: Same circuit used for QSOP16 option but with adjusted pinout.
ISSUE 1 - JUNE 2001
5
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