Zetex ZNBG3010Q16, ZNBG3011Q16 Datasheet
FET BIAS CONTROLLER AND
POLARITY SWITCH
ISSUE 1 - FEBRUARY 1998
ZNBG3010
ZNBG3011
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
and current control for 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 -3 volts, can also be
used to supply other external circuits.
The ZNBG3010/11 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
particularly used as an LNB polarisation
switch.
Drain current setting of the ZNBG3010/11 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
ZNBG3010 gives 2.2 volts drain whilst the
ZNBG3011 gives 2 volts.
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
•
QSOP surface mount package
•
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 FET bias controls, unused
drain and gate connections can be left open
circuit without affecting operation of the
remaining bias circuits.
In order to protect the external FETs the
circuits have been designed to ensure that,
under any conditions including power
up/down transients, the gate drive from the
bias circuits cannot exceed the range -3.5V
to 1V. 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 ZNBG3010/11 are available in QSOP16
for the minimum in device size. Device
operating temperature is -40 to 70°C to suit
a wide range of environmental conditions.
APPLICATIONS
Satellite receiver LNBs
•
Private mobile radio (PMR)
•
Cellular telephones
•
4-114
ZNBG3010
ZNBG3011
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 70°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 to ID3=0
Substrate Voltage
(Internally generated)
Output Noise
Drain Voltage
Gate Voltage
Oscillator Frequency 200 350 800 kHz
= = 25°C,VCC=5V,ID=10mA (R
amb
and ID3=10mA, V
I
D2
and ID3=10mA, V
I
D1
I
=0
SUB
=-200µA
I
SUB
=4.7nF, CD=10nF
C
G
=4.7nF, CD=10nF
C
G
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) (µµA)
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
=8 I
I
D3
Power Dissipation (T
QSOP16 500mW
=14V
POL
=15.5V
POL
I
GOx
=14 I
=15.5 I
=15.5 I
=15.5 I
=14 I
=14 I
GO1
GO1
GO1
GO2
GO2
GO2
GO3
GO3
=-10
=-10
=0
=-10
=-10
=0
=-10
=0
= = 25°C)
amb
=33kΩΩ)
CAL
LIMITS
MIN. TYP. MAX.
10
30
30
-3.5 -3.0 -2
-2
0.02
0.005
-3.5
-3.5
0.4
-3.5
-3.5
0.4
-3.5
0.4
-2.9
-2.9
0.75
-2.9
-2.9
0.75
-2.9
0.75
-2.0
-2.0
1.0
-2.0
-2.0
1.0
-2.0
1.0VV
UNITS
mA
mA
mA
V
V
Vpkpk
Vpkpk
µA
V
V
V
V
V
V
4-115
ZNBG3010
ZNBG3011
SYMBOL PARAMETER CONDITIONS
LIMITS
UNITS
MIN. TYP. MAX.
DRAIN CHARACTERISTICS
I
DI
DI
V
V
V
DV
DV
I
I
D
DV
DT
D1
D2
D3
DV
DT
L1
L2
Current 8 10 12 mA
Current Change
with V
with T
CC
j
VCC= 5 to 10V
T
=-40 to +70°C
j
0.2
0.05
%/V
%/°C
Drain 1 Voltage:High
ZNBG3010
ZNBG3011
=10mA, V
I
D1
I
=10mA, V
D1
POL
POL
=15.5V
=15.5V
2.0
1.8
2.2
2.0
2.4
2.2VV
Drain 2 Voltage:High
ZNBG3010
ZNBG3011
I
=10mA, V
D2
=10mA, V
I
D2
POL
POL
=14V
=14V
2.0
1.8
2.2
2.0
2.4
2.2VV
Drain 3 Voltage:High
ZNBG3010
ZNBG3011
=10mA, V
I
D3
I
=10mA, V
D3
POL
POL
=15.5V
=15.5V
2.0
1.8
2.2
2.0
2.4
2.2VV
Voltage Change
with V
with T
CC
j
VCC= 5 to 10V
=-40 to +70°C
T
j
0.5
50
%/V
ppm
Leakage Current
Drain 1
Drain 2
V
D1
V
D2
=0.1V, V
=0.1V, V
POL
POL
=14V
=15.5V
10
10
µA
µA
POLARITY SWITCH CHARACTERISTICS
I
POL
V
TPOL
T
SPOL
Notes:
1. The negative bias voltages specified are generated on-chip using an internal oscillator. Two external
capacitors, C
2. The characteristics are measured using an external reference resistor R
pins R
3. Noise voltage is not measured in production.
4. Noise voltage measurement is made with FETs and gate and drain capacitors in place on all
outputs. C
between drain outputs and ground.
Input Current V
Threshold Voltage
=25V
POL
(Applied via R
(Applied via R
POL
POL
=10kΩ
=10kΩ
10 20 40
14 14.75 15.5 V
Switching Speed 100
and C
NB
to ground.
CAL
, 4.7nF, are connected between gate outputs and ground, CD, 10nF, are connected
G
, of 47nF are required for this purpose.
SUB
of value 33k wired from
CAL
µA
µs
4-116
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