SA616
Low-voltage high performance mixer FM IF system
Rev. 5 — 24 July 2012
Product data sheet
1. General description
The SA616 is a low-voltage high performance monolithic FM IF system incorporating a
mixer/oscillator, two limiting intermediate frequency amplifiers, quadrature detector,
logarithmic Received Signal Strength Indicator (RSSI), voltage regulator and audio and
RSSI op amps. The SA616 is available in SSOP20 and HVQFN20 packages.
The SA616 was designed for portable communication applications and will function down
to 2.7 V. The RF section is similar to the famous SA615. The audio and RSSI outputs
have amplifiers with access to the feedback path. This enables the designer to adjust the
output levels or add filtering.
2. Features and benefits
Low power consumption: 3.5 mA typical at 3 V
Mixer input to >150 MHz
Mixer conversion power gain of 17 dB at 45 MHz
XTAL oscillator effective to 150 MHz (LC oscillator or external oscillator can be used at
higher frequencies)
102 dB of IF amp/limiter gain
2 MHz IF amp/limiter small signal bandwidth
Temperature compensated logarithmic RSSI with a 80 dB dynamic range
Low external component count; suitable for crystal/ceramic/LC filters
Excellent sensitivity: 0.31
V
into 50
matching network for 12 dB SINAD
(Signal-to-Noise-and-Distortion ratio) for 1 kHz tone with RF at 45 MHz and IF at
455 kHz
SA616 meets cellular radio specifications
Audio output internal op amp
RSSI output internal op amp
Internal op amps with rail-to-rail outputs
ESD protection exceeds 2000 V HBM per JESD22-A114 and 1000 V CDM per
JESD22-C101
Latch-up testing is done to JEDEC Standard JESD78 Class II, Level B
3. Applications
Portable cellular radio FM IF
Cordless phones
Wireless systems
RF level meter
NXP Semiconductors
SA616
Low-voltage high performance mixer FM IF system
Spectrum analyzer
Instrumentation
FSK and ASK data receivers
Log amps
Portable high performance communication receiver
Single conversion VHF receivers
4. Ordering information
Table 1.
Ordering information
T
amb
=
40
C to +85
C
Type number
SA616DK/01
SA616BS
Topside
mark
SA616DK
616B
Package
Name
SSOP20
HVQFN20
Description
plastic shrink small outline package; 20 leads;
body width 4.4 mm
Version
SOT266-1
plastic thermal enhanced very thin quad flat package; no leads; SOT917-1
20 terminals; body 4
4
0.85 mm
5. Block diagram
20
(18)
19
(17)
18
(16)
17
(15)
16
(14)
15
(13)
14
(12)
13
(11)
12
(10)
11
(9)
IF amp
mixer
limiter
OSC
RSSI
quad
VREG
E
3
(1)
B
4
(2)
audio
1
(19)
2
(20)
5
(3)
6
(4)
7
(5)
8
(6)
9
(7)
10
(8)
002aaf352
Pin numbers for SSOP20; HVQFN20 pins shown in parentheses.
Fig 1.
Block diagram of SA616
SA616
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2012. All rights reserved.
Product data sheet
Rev. 5 — 24 July 2012
2 of 31
NXP Semiconductors
SA616
Low-voltage high performance mixer FM IF system
6. Pinning information
6.1 Pinning
RF_IN
RF_IN_DECOUPL
OSC_OUT
OSC_IN
RSSI_OUT
V
CC
AUDIO_FEEDBACK
AUDIO_OUT
RSSI_FEEDBACK
1
2
3
4
5
6
7
8
9
20 MIXER_OUT
19 IF_AMP_DECOUPL
18 IF_AMP_IN
17 IF_AMP_DECOUPL
16 IF_AMP_OUT
15 GND
14 LIMITER_IN
13 LIMITER_DECOUPL
12 LIMITER_DECOUPL
11 LIMITER_OUT
002aaf350
SA616DK/01
QUADRATURE_IN 10
Fig 2.
Pin configuration for SSOP20
17 IF_AMP_DECOUPL
20 RF_IN_DECOUPL
18 MIXER_OUT
terminal 1
index area
OSC_OUT
OSC_IN
RSSI_OUT
V
CC
AUDIO_FEEDBACK
1
2
3
4
5
DAP
(1)
LIMITER_DECOUPL 10
6
7
8
9
16 IF_AMP_IN
15 IF_AMP_DECOUPL
14 IF_AMP_OUT
13 GND
12 LIMITER_IN
11 LIMITER_DECOUPL
SA616BS
RSSI_FEEDBACK
19 RF_IN
QUADRATURE_IN
AUDIO_OUT
LIMITER_OUT
002aaf351
Transparent top view
(1) Die Attach Paddle (DAP).
Fig 3.
Pin configuration for HVQFN20
SA616
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2012. All rights reserved.
Product data sheet
Rev. 5 — 24 July 2012
3 of 31
NXP Semiconductors
SA616
Low-voltage high performance mixer FM IF system
6.2 Pin description
Table 2.
Symbol
RF_IN
RF_IN_DECOUPL
OSC_OUT
OSC_IN
RSSI_OUT
V
CC
AUDIO_FEEDBACK
AUDIO_OUT
RSSI_FEEDBACK
QUADRATURE_IN
LIMITER_OUT
LIMITER_DECOUPL
LIMITER_DECOUPL
LIMITER_IN
GND
IF_AMP_OUT
IF_AMP_DECOUPL
IF_AMP_IN
IF_AMP_DECOUPL
MIXER_OUT
-
[1]
Pin description
Pin
SSOP20
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
-
HVQFN20
19
20
1
2
3
4
5
6
7
8
9
10
11
12
13
[1]
14
15
16
17
18
DAP
RF input
RF input decoupling pin
oscillator output
oscillator input
RSSI output
positive supply voltage
audio amplifier negative feedback terminal
audio amplifier output
RSSI amplifier negative feedback terminal
quadrature detector input terminal
limiter amplifier output
limiter amplifier decoupling pin
limiter amplifier decoupling pin
limiter amplifier input
ground; negative supply
IF amplifier output
IF amplifier decoupling pin
IF amplifier input
IF amplifier decoupling pin
mixer output
exposed die attach paddle
Description
HVQFN20 package supply ground is connected to both GND pin and exposed center pad. GND pin must
be connected to supply ground for proper device operation. For enhanced thermal, electrical, and board
level performance, the exposed pad needs to be soldered to the board using a corresponding thermal pad
on the board and for proper heat conduction through the board, thermal vias need to be incorporated in the
PCB in the thermal pad region.
SA616
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2012. All rights reserved.
Product data sheet
Rev. 5 — 24 July 2012
4 of 31
NXP Semiconductors
SA616
Low-voltage high performance mixer FM IF system
7. Functional description
The SA616 is an IF signal processing system suitable for second IF systems with input
frequency as high as 150 MHz. The bandwidth of the IF amplifier and limiter is at least
2 MHz with 90 dB of gain. The gain/bandwidth distribution is optimized for 455 kHz,
1.5 k source applications. The overall system is well-suited to battery operation as well
as high performance and high quality products of all types.
The input stage is a Gilbert cell mixer with oscillator. Typical mixer characteristics include
a noise figure of 6.2 dB, conversion gain of 17 dB, and input third-order intercept of
9
dBm. The oscillator will operate in excess of 200 MHz in L/C tank configurations.
Hartley or Colpitts circuits can be used up to 100 MHz for crystal configurations. Butler
oscillators are recommended for crystal configurations up to 150 MHz.
The output impedance of the mixer is a 1.5 k resistor permitting direct connection to a
455 kHz ceramic filter. The input resistance of the limiting IF amplifiers is also 1.5 k. With
most 455 kHz ceramic filters and many crystal filters, no impedance matching network is
necessary. The IF amplifier has 43 dB of gain and 5.5 MHz bandwidth. The IF limiter has
60 dB of gain and 4.5 MHz bandwidth.
To achieve optimum linearity of the log signal strength indicator, there must be a 12 dBV
insertion loss between the first and second IF stages. If the IF filter or interstage network
does not cause 12 dBV insertion loss, a fixed or variable resistor or an L pad for
simultaneous loss and impedance matching can be added between the first IF output
(IF_AMP_OUT) and the interstage network. The overall gain will then be 90 dB with
2 MHz bandwidth.
The signal from the second limiting amplifier goes to a Gilbert cell quadrature detector.
One port of the Gilbert cell is internally driven by the IF. The other output of the IF is
AC-coupled to a tuned quadrature network. This signal, which now has a 90 phase
relationship to the internal signal, drives the other port of the multiplier cell.
The demodulated output of the quadrature drives an internal op amp. This op amp can be
configured as a unity gain buffer, or for simultaneous gain, filtering, and second-order
temperature compensation if needed. It can drive an AC load as low as 5 k with a
rail-to-rail output.
A log signal strength completes the circuitry. The output range is greater than 90 dB and is
temperature compensated. This log signal strength indicator exceeds the criteria for
AMPS or TACS cellular telephone. This signal drives an internal op amp. The op amp is
capable of rail-to-rail output. It can be used for gain, filtering, or second-order temperature
compensation of the RSSI, if needed.
Remark:
dBV = 20log V
O
/V
I
.
SA616
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2012. All rights reserved.
Product data sheet
Rev. 5 — 24 July 2012
5 of 31