Table Of ContentCONFIDENTIAL B
MT6631
BT/WiFi/GPS/FM
Design Notice
V1.1
2018.04.16
Document Change List
Version Dateofchange Descriptionofchange Page
V0.1 20150630 Initial updated from MT6631 design notice V0.1
V0.2 20151117 Update bypass cap value sync with reference schematic 8,9
V0.3 20160126 Correct some wording about different platform supported 26
Update the rule that avoid the audio noise de-sense to FM Add 24
LTE B39 to GPS system level de-sense Add 34~37
V1.0 201601024 WiFi2.4G BAW/FBAR matching Design Guide Add 34~35
Change power domain description, add Vcore, AVDD12_WBG 8
New chip GPS use single-ended design 15,27
FM circuit add MT6355 design 25
V1.1 20180416 Correct VSWR define 18
Correct FM control block diagram 4
Remove co-rx feature 5
Update GPS description 6, 12, 15
Update GPS application design 21
Update LTE B34/B39 and GPS co-existence 39
Update WiFi2.4G BAW/FBAR matching Design Guide 36
CONFIDENTIAL B 2
Agenda
MT6631 Block Diagram
MT6631 Performance & Feature Overview
MT6631 sub-system application circuit guide
Control and IQ interface Application Design
WiFi/BT Application Design
GPS Application Design
FM Receiver Application Design
MT6631 sub-system Layout Guide
MT6631 system level de-sense design guide
Primary MT6631 documents
CONFIDENTIAL B 3
MT6631 Block Diagram
FM Antenna
XO in Always-On FM Rx IPD
LDO
FM FM Rx FM RX
DSP Modem RF+AFE Pin 38
FM ant in
FM 2-wire
1.6G Antenna
GPS RF
GRxP SIQ GPS RF LNA MN Pin 39 LNA
GPS
RF in
GPS 2-wire
GPS dig
5G WiFi RF
A
N AUX_5G
5G L
3-wire 5G RF
Ctrl TRx A 5G Pin 35
LN TRS Pin 34 5RGF W IOiFi 5G / 2.4G
5G PA W Antenna
PTA
Control
External
Filter /
Diplexer
2.4G WiFi/BT RF
WiFi Tx/Rx IQ ux
M PA NC
BT Tx/Rx IQ WBiFTi / NA RSW BMa+lNun 2.4G PPiinn 3312 2.4G
Shared L T RF I/O
TOP & WBT RF A
2-wire 2-wire 2-wire TRx LN
Ctrl Ctrl Co-RX
2.4/ 5G WiFi A Pin 30
& BT RF PTA / N AUX_2G
dedicated WBT L
control Control
CONFIDENTIAL B 4
MT6631 block diagram
MT6631 Feature
▪ General
• MT6631 is a 4-in-1 connectivity RF chip which contains front-ends of a 2.4GHz Wi-Fi and
Bluetooth transceiver, a 5GHz Wi-Fi transceiver, a GPS receiver and an FM receiver.
• MT6631 supports integrated passive device to save footprint on PCB and cost due to
Wi-Fi/Bluetooth/GPS external BoM (bill of materials) in a 40-pin QFN package.
▪ Wi-Fi / BT
• Simultaneous operation (FDD) of WiFi-5GHz and Bluetooth.
▪ Wi-Fi
• Dual-band (2.4GHz and 5GHz) single stream 802.11 a/ b/g/n/ac RF, 20/40/80MHz
bandwidth
• Supports worldwide Wi-Fi 5G channel including new band in US and China (5925MHz),
and Bluetooth FDD operation
• Integrated 2.4GHz PA with max. 20dBm CCK output power,
5GHz PA OFDM 54Mbps output power 17dBm and VHT80 MCS9 output power 15dBm.
• Typical Rx sensitivity with companion chip modem: -76.5dBm at both 11g 54Mbps
mode and 11a 54Mbps mode, -62dBm at 11ac VHT80 MCS9 mode
• Integrated power detector to support per packet Tx power control
• Supports external PA and LNA for WiFi-2.4GHz and WiFi-5GHz.
CONFIDENTIAL B 5
MT6631 Feature
▪ Bluetooth
• Bluetooth specification v2.1+EDR, 3.0+HS and v4.1+HS compliant
• Integrated PA with 8dBm (class 1) transmit power
• Typical Rx sensitivity with companion chip modem: GFSK -94dBm, DQPSK -93dBm, 8-DPSK -87.5dBm
▪ ANT/ANT+
• The wireless protocol standard for sport and fitness monitors
• Supports different profiles for various applications: sport & fitness, health & wellness, recreational
activity, transportation, and information management, etc.
▪ FM
• 65 -108MHz with 50kHz step
• Supports RDS/RBDS
• Digital stereo modulator/demodulator
• Digital audio interface
▪ GPS
• RF supports GPS, Galileo, GLONASS, and Beidou.
• Simultaneous reception of GPS + Galileo + GLONASS + Beidou for more accurate positioning. (note:
MT6765 series platform)
• Typical RX tracking sensitivity of -165dBm.
• Support external LNA
CONFIDENTIAL B 6
Pin 36: FM 2V8
MT6631 Pin-out
Pin 37: FM RF_N
Pin 38:FM_RF_P
Pin 33: WiFi/BT 3V3
Pin39: GPS RF
Pin30,31,34,35
WiFi / BT RF pin
Pin40: GPS 1V8 &
6631 Top logic power
Pin 28~29:
WiFi ePA Feedback
voltage detect
Host reset
Package type: QFN 40-lead
Package size: 5 x 5mm2 Pin 26~Pin27:
Top digital control
WiFi/BT 1V8
WiFi/BT
System clock input
control line
NOT Support Xtal !!
Pin 9~12: GPS I/Q
Pin 13~16: BT IQ
Pin17~20: WiFi IQ
CONFIDENTIAL B 7
MT6631 Power Scheme
ForPMICLDOstabilityRequirement:
MT6797 10uF, others 4.7uF
VCN33 WBT_3V3
1uF 4.7uF 100pF
VCN28
FM_2V8
10nF
MT6631
Star Connection
(Connectivity RF)
VCN18
WBT_1V8
1uF 100nF 100pF
PMIC
PMIC side bypass cap GPS_1V8
please refer to
4.7nF
PMIC design notice
Other IP
VCore VCCK BB Chip
Large cap
(Connectivity digital)
Other IP
VIO18 AVDD18_WBG
Large cap 100nF
Other IP
VA12 AVDD12_WBG
Large cap 100nF
AVDD18_GPS 20mA :10mil MT6797 doesn’t have AVDD12_WBG
AVDD18_WB 50mA:10mil power domain
AVDD28_FM 20mA:6~8mil
AVDD33_WB Max 500mA : ≧ 12mil is better(more than 2 VIAs when change layer)
As wide as possible L/W ≦ 2800/12
CONFIDENTIAAL BVDD18_WBG 35mA:10mil(MT6797), 25mA:8~10mil (others) 8
AVDD12_WBG 10mA:6mil
MT6631 Power Scheme-2
PMIC MT6631
FM_2V8
VCN28
1uF 10nF
TCXO
10nF
GPS LNA
10nF
1. VCN28 total bypass cap must bigger than 1uF and
smaller than 2.1uF for LDO stability.
CONFIDENTIAL B 9
MT6631 Host Interface
CONN 2-wire
Pin #3, #4
WB PTA
Pin #5
Reset fromHost
Pin #2
GPS I/Q
Pin #9~ #12
Host Connectivity
BT T/Rx I/Q
BB chip RF chip
Pin #13~ #16
(Connectivity digital) MT6631
WiFi T/Rx I/Q
Pin #17~ #20
WiFi 3-wire hi-speed
command line
Pin #21~ #23
BT 2-wire
command line
Pin #24~ #25
CONFIDENTIAL B 10
