Modes of Operation6
DC Characteristics7
AC Characteristics8
External Signals and Connections9
Internal Signals and Connections11
Mechanical Characteristics12
User Interface Features12
Charge States and Charge Control13
Charge Indication to User13
Environmental Conditions15
Temperature Conditions15
Functional Description16
Circuit Description (DC3H)18
Control Logic18
Watchdog Function21
Switch Mode Power Supply (SMPS)21
Battery Charging21
Spare Battery Discharging22
Microphone Amplifier and Corresponding Switches22
Speaker Amplifier and Corresponding Switches22
Circuit Description (DC4H)22
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Handsfree Desktop Charger CHH–7
Technical Documentation
Assembly23
DC3H ModuleParts List24
DC4H Module Parts List32
The CHH–7 Handsfree Desktop Charger provides both charging and
handsfree facilities. The charger enables a phone plus a spare battery to
be charged; the spare battery is charged after the phone battery has been
charged. CHH–7 can only be powered by the AC Power Supply
(ACS–6U/X/E); the supply is connected to the charger via a socket at the
rear of the charger.
Analogue data accessories may be used in conjunction with the
Handsfree Desktop Charger; a connector at the rear of the charger is
provided for this purpose.
The BABT approved version of CHH–7 is known as CHH–7X. Since both
units are technically identical, all references to CHH–7 equally apply to
CHH–7X.
Handsfree Desktop Charger CHH–7
Technical Summary
Operation
CHH–7 consists of a spare battery charging control processor, charging
indicators and a switched mode power supply for charging the phone and
the spare battery. The unit has an in–built hf–speaker and hf–microphone
but the handsfree function is generated in the phone. There are also
three operating buttons: the front one is a MUTE button for the CHH–7
microphone; the middle one is for redialling the last number dialled; and
the rear one is for selecting the spare battery discharge.
List of Modules
Table 1. List of Modules
NAME OF MODULETYPE
CODE
HF Deskstand ChargerCHH–70675040Fully Assembled Charger
HF Desktop Charger and
Connector Module
HF Desktop ChargerDC3H0200334Main Electronic Components and Connector
DCXH0200335A single PCB biscuit containing both the HF Desktop
MATERIAL
CODE
NOTES
Charger and Connector Module
Connector ModuleDC4H0200295System Connectors, Data Buffer and Noise Comp
Assembly PartsMCHH70260338Mechanical Parts,Speaker, Microphone and Flex Foils
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Handsfree Desktop Charger CHH–7
Basic Specifications
Table 2. Basic Specifications
Power Consumption13W max.
Input Voltage Range13.5V to 21.0V
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Technical Documentation
Battery Charger:Output Voltage
Output Current
Maximum Charging Time (empty battery):BTH–8S (400mAh):45min
Maximum Discharging Time (full battery):BTH–8S (400mAh):3h 30min
Operating Temperature+5C to +55C
Charging Temperature+5C to +45C (40C when fitting battery)
Speaker Output Powernominal: 1W / 8ohm
External Main Dimensions43mm (H) x 167mm (W) x 113mm (D)
Weight360g
NOTE:To ensure the battery is fully charged, it is recommended to
continue charging for 2 to 3 hours after a fast charge has
been completed.
Technical Specifications
Modes of Operation
Power Off Mode:The unit receives no power at the DC–
connector.
Standby Mode:The unit receives the supply voltage at
the DC–connector. The processor is
running but because there isn’t a phone
or spare battery in the cradle, the
charger remains off and the audio
functions are inactive.
Active Mode:The telephone or spare battery is in the
cradle so the charging functions are
active. Normally the handsfree speaker
is muted. During a call and during the
key beeps or alarming tones the
speaker and corresponding audio
switches are open.
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Technical Documentation
DC Characteristics
Table 3. Supply Voltages and Power Consumption on the Connectors of CHH–7
Handsfree Desktop Charger CHH–7
CONNECTOR
Pin/Connector
DC
1 / X100
SPARE
BATTERY
X101, X102
X103, X104
SYSTEM
10 / X701
DATA Analogue
2 / X510
Table 4. Supply Voltages and Power Consumptions on the DC3H–module
SYMBOL/
MODULE
+VIPower Supply13.5V13.8V21.0V
+VCCCharging voltage for the
+10VASupply for logic and
+10VASSwitched supply for logic
+5VSupply for logic
+5VREFReference voltage for uP4.9V5.0V5.1V
+5VLDSupply voltage for LEDs4.9V5.0V5.1V
+5VANSupply for analogue parts 4.6V5.0V5.1V
+VAREFReference voltage for
LINE SYMBOLMINIMUMTYPICAL/
VDC
Input Voltage
Input Power
VBAT
Charging:
Output Voltage
Output Current
Discharging:
Input Voltage
Input Current
VC
Charging:
Output Voltage
Output Current
VD
Output Voltage
Output Current
PARAMETERMINIMUMTYPICAL/
battery
analogue parts
and analogue parts
parts
analogue parts
13.5V13.8V21.0V
11.0V
730mA
5.0V
130mA
11.0V
730mA
9.6V10.0V10.4V
10.3V
730mA
9.6V10.0V10.4V
9.1V9.8V10.2V
4.9V5.0V5.1V
2.2V2.5V2.7V
NOMINAL
12.2V
800mA
6.0V
160mA
12.2V
800mA
NOMINAL
11.5V
800mA
MAXIMUM
13.0W
13.0V
870mA
7.5V
200mA
13.0V
870mA
50.0mA
MAXIMUM
13W
13.3V
870mA
250mA
250mA
35mA
1.5mA
30mA
1mA
0.1mA
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Handsfree Desktop Charger CHH–7
AC Characteristics
Table 5. External Microphone signal
XMIC (1 kHz)TYPICAL/NOMINAL
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Technical Documentation
Cable level
0 dBmO
Table 6. Handsfree Microphone Signal
HFMIC (1 kHz)TYPICAL/NOMINAL
MRP+15.3dBPa / 50 cm (Mic Ref Point)
HFMICinput–4.7dBPa (approx 20dB attenuation)
Gain for HFMIC40dB
Cable Level200mV
DC4H–module: 50 x 1.6 x 22PCB has 6 layers / 1.6 mm
User Interface Features
Charging takes place at a battery temperatures of between 5 and 45.
Control of the charging process for the phone is performed by a
microprocessor located inside the phone; control of the charging process
for the spare battery is performed by a separate microprocessor located in
the HF desktop charger. The phone is always charged first, followed by
the spare battery. When a spare battery is fitted, the temperature must be
less than 40
A battery provides a larger capacity if it is occasionally discharged
completely. The user can do this by using the ‘deep discharge‘ feature.
This feature only operates with the spare battery slot. With the battery
located in the spare slot, the spare battery will automatically be
discharged and then re–charged to full capacity when the ‘discharge‘
–button is depressed. If this button is pressed twice the discharge
function is cancelled.
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Technical Documentation
Charge States and Charge Control
Charge current for the phone is supplied through a series connected
switching transistor located in the phone. When this transistor is on, the
charger is supplying a constant current to the phone. This is the rapid
charge mode.
When the transistor is off, no current is supplied to the phone and the
charger is in the constant voltage mode.
Having been charged up in the rapid charge mode, the battery is kept fully
charged by using pulsed charging, ie. switching power alternately on and
off at a variable duty cycle and a frequency of a few Hz.
The desktop charger also contains control logic for spare battery charging,
which is enabled when no phone is connected or when the phone is in the
pulsed charge mode. When the phone is in pulse charge mode the spare
battery can only be charged at 70% of the rate when no phone is present.
Handsfree Desktop Charger CHH–7
Charge Indication to User
The desktop charger has dual–colour LEDs to indicate the charge state of
the phone and the spare battery, the right hand LED is for the phone and
the left hand LED is for the spare battery. The LEDs are off when there is
no phone or spare battery connected.
Right LED for phone:
Red phone LED indicates that the phone battery is being charged in fast
charge mode or charging is disabled due to battery temperature being
outside permissible range.
Green phone LED indicates that the phone battery is full and that trickle
charge mode is active.
Left LED for spare battery:
Red spare battery LED indicates that the battery is not full; either there is
a fast charge mode active or charging is disabled due to a battery
temperature ’fault’ or the phone is being fast charged.
Green spare battery LED indicates that the battery is fully charged.
Flashing red spare battery LED indicates that a discharge cycle is active.
The liquid–crystal display of the phone also contains a three–bar battery
charge display. ”Charging sequence active” (state A) is indicated by the
bars illuminated sequentially, starting from the bottom bar (each bar is on
for a period of 1 s).
”Battery full” (state B) is indicated by all three bars steadily illuminated.
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Handsfree Desktop Charger CHH–7
Technical Documentation
Table 20. Phone Operating Status
PHONE OPERA TING STA TUSRIGHT HAND LEDPHONE DISPLAY
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Desktop charger connected to mains
through ac adapter, phone
disconnected
Rapid charge or waiting for the
right temperature (+5C to +45C)
Battery full – trickle chargegreenstate B (all bars steadily
Table 21. Spare Battery Operating Status
SPARE BATTERY OPERATING STATUSLEFT HAND LED
Desktop charger connected to mains through ac adapter, spare battery
disconnected
Rapid charge of spare battery or waiting for the phone charging ready or for
the right temperature
Spare battery full – trickle chargegreen
Discharge of spare batteryflashing red
––
redstate A (bars illuminated
sequentially)
illuminated)
–
red
Handsfree Function
When located in the charger, the phone always operates in handsfree
mode; the charger’s internal HF speaker and HF microphone being active
during the call. It is also possible to switch between handsfree and
handset operation while a call is in progress. This is done by removing
the phone from the charger (to return to handset operation) or placing it in
the charger (to return to handsfree operation).
The HF speaker volume is adjusted using the volume keys located on the
side of the phone. The HF volume level is set independently from the
phone’s internal earpiece volume; the HF volume setting is stored in the
phone’s memory when the phone is removed from the charger. The HF
microphone audio can be muted by pressing the mute key on the front
edge of the charger. The muted state is indicated by the message
”MUTE” appearing on the phone’s display. Pressing the ”MUTE” key a
second time cancels the mute function.
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Technical Documentation
Environmental Conditions
Temperature Conditions
Table 22. Allowed Ambient Temperature
ENVIRONMENTAL PARAMETERVALUE
Handsfree Desktop Charger CHH–7
Operating Temperature
Storage Temperature
– 5 to + 55°C
(charging: + 5 to + 45°C)
– 40 to + 85°C
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Handsfree Desktop Charger CHH–7
Functional Description
Figure 1: Block Diagram
DC CONNECTOR
CHARGER
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Technical Documentation
CHH–7
MODULE
PHONE
CHARGING
INDICATION
MODULE
SPARE BATTERY CONNECTOR
SPARE
BATTER Y
CHARGE /
DISCHARGE
CONTROL
BUTTONS
PROCESSOR
CHARGING LEDs
RFI
FILTER
COMP.
SYSTEM CONNECTOR
AUDIO
DATA CONNECTOR
SPEAKERHFMIC
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Technical Documentation
Figure 2: Component Location Diagram
Handsfree Desktop Charger CHH–7
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Handsfree Desktop Charger CHH–7
Circuit Description (DC3H)
The DC3H–Module consists of the following functional blocks:
– Supply Voltages
– Control Logic
– Battery Charging
– Spare Battery Discharging
– Watchdog Function
– Switch Mode Power Supply
– Microphone Amplifier and corresponding switches
– Speaker Amplifier and corresponding switches
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Technical Documentation
Refer to Figures 4 and 5 for DC3H circuit diagrams (sheets 1 and 2).
Control Logic
Charging is controlled by processor D300. The D300 is a single–chip type
controller incorporating RAM, ROM, an A/D converter, and a multifunction
timer/counter. The processor communicates with the phone via the
M2BUS. The M2BUS interface comprises transistors V200, V201 and
corresponding resistors.
Table 23. Port A Signals of the Processor:
PORT ANOTES
P A0: PHONE GREEN(output)Phone LED control, green: ”1”
P A1: PHONE RED(output)Phone LED control, red: ”1”
P A2: SP ARE GREEN(output)Spare battery LED control, green: ”1”
P A3: SPARE RED(output)Spare battery LED control, red: ”1”
P A4: DISCHARGE BUTTON(input)Discharge button control,
”0”: start / stop discharge
P A5: SP ARE DISCHARGE(output)Discharge spare battery ,
”1”: discharge enabled
PA6: Unused(output)Not Used
PA7: CHARGER(output)Charger Switch, ”1”: charger on
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⇒ CHH–7
Handsfree Desktop Charger CHH–7
Technical Documentation
Table 24. Port B Signals of the Processor: (continued)
PORT BNOTES
PB0: SERVICE J301(output)See next table
PB1: SERVICE J302(output)See next table
PB2: SERVICE J303(output)See next table
PB3: SERVICE J304(output)See next table
PB4: SERVICE J305(output)Not Used
PB5: LAST NUMBER REDIAL (input)Last Number Redial button, ”0”: activation
PB6: HFMIC MUTE(input)HF Microphone Muting, ”0”: activation
PB7: PHONE IDENTIFICATION(input)pulled up +5V (= state ”1”)
Table 25. Service Test Pins of Port B:
J304J303J302J301NOTES
0001Battery voltage hi limit reached
0010Maximum charge time
0011Voltage drop (delta V)
0100Battery temperature high
0101Constant voltage
PC5: DVCE1(input)
PC6: SP ARE CHARGE(output)Spare Battery Charging, ”1”: Charging on
Device Type ”1”
”
Device Type ”0”
”
PC7: WATCHDOG(output)Watchdog Reset, ”01010...”: Watchdog reset on
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Handsfree Desktop Charger CHH–7
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Technical Documentation
Table 27. Port D Signals of the Processor:
PORT DNOTES
PD0: PHONE MIC(output)analogue Switch, ”1”: Phone mic switched on
PD1: ACC MIC(output)analogue Switch, ”1”: Accessory mic switched on
PD2: HF MIC(output)analogue Switch, ”1”: HF mic switched on
PD3: PHONE EAR(output)analogue Switch, ”1”: Phone ear switched on
PD4: ACC EAR(output)analogue Switch, ”1”: Accessory ear switched on
PD5: HF SPK(output)analogue Switch, ”1”: HF speaker switched on
PD6: Unused(output)Not Used
PD7: Unused(output)Not Used
Table 28. Port F Signals of the Processor:
PORT FNOTES
PF0: Unused(input)Not Used
PF1: Unused(input)Not Used
PF2: Unused(input)Not Used
PF3: Unused(input)Not Used
PF4: Unused(input)Not Used
PF5: Unused(input)Not Used
PF6: Unused(input)Not Used
PF7: Unused(input)Not Used
Table 29. Processor A/D Inputs:
NAMENOTES
AN0: VBATLBattery voltage
AN1: VBATHHigh resolution battery voltage
AN2: PHOCURDETPhone current detect
AN3: BATTEMPBattery temperature
AN4: BATTSZBattery size
AN5: CHRGVOLTCharger voltage detection
AN6: PWRPhone connection detection
AN7: LIREFNot Used
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Watchdog Function
Under normal operating conditions the processor is pulsating the
WATCHDOG–line in order to reset the power–off function of regulator
N102. If the processor is not functioning correctly and hence the regulator
does not send the pulse to the XPWROFF–line within the 100ms timeout
period, the regulator reverts to its power–off state resetting the processor
and switching the VAREF and +VAN voltages off. The regulator and the
processor can be restarted by pressing the discharge button (S300) once
or switching the power supply (connected to X100) off and on. The supply
voltage (+VA) for the regulator must be greater than 8.1V in order for the
regulator to switch on.
Switch Mode Power Supply (SMPS)
C100 and C101 are the EMI capacitors. L100 and L101 are EMI
suppressor chokes. V100 is the voltage suppressor (zener) diode.
Handsfree Desktop Charger CHH–7
The microprocessor D300 pin 2 starts the SMPS by starting reference
regulator N103. V115–1 leads the initial current to totally empty the
battery. V106 is a constant current source which sets the voltage value of
R118. The same voltage appears across the current shunt resistor R103
when the SMPS is working. N101–a is a pulse width modulator. N101–b,
together with R122, C103 and V114–1, generates a minimum pulse width.
R127 and R521 are input and output voltage correction resistors. V103
limits the comparator power supply +VS. V115–2 and V372 limits the
comparator output voltage. V341–1 and C341 form a bootstrap circuit,
which acts like a voltage doubler and generates the positive gate voltage
to switch the fet V102 gate. L111 (L109), R130 and C340 are
EMI–suppression components. L108 is the main SMPS inductor. V110
limits the maximum output voltage.
Battery Charging
Charging current for the phone battery is supplied when the processor
switches the SMPS on after the phone is connected to the system
connector X701 on the DC4H module. The charger voltage should be
between 13.5V and 21.0V. The phone battery’s charging state is indicated
by the red (V344 / V345) and green (V333) LEDs. Because the phone
and the spare battery cannot be charged simultaneously, the charging
current of the phone must be detected: this is achieved by a differential
amplifier (N250–A) and corresponding resistors.
Charging current for the spare battery is fed in via switching transistor
V221 and Schottky diode V220. The transistor is controlled by the
processor. When the phone battery is not being charged and hence the
spare battery is allowed to charge, the transistor is on and a constant
current is supplied to the battery (the red LED V331 lights). In the pulsed
charging mode, charging current is adjusted by pulsing this charge current
(the green LED V330 lights).
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Handsfree Desktop Charger CHH–7
Spare battery voltage and V voltage are determined by reading the
VBAT line state. Voltages are measured through resistor divider R250 /
R251 and the amplifier N250–B.
Spare battery size is determined by reading the BSI line state. This is
pulled to the +5V reference voltage by R243. In the battery pack a ’size’
resistor is connected between BSI and GND.
Temperature is measured over the BTEMP line. This line is pulled to the
+5V reference voltage by R242. In the battery pack an NTC resistor is
connected between BTEMP and GND.
Spare Battery Discharging
The HF desktop charger is also provided with a discharge function. This
is activated by pressing the discharge button S300. Resistors R230 to
R237 determine the discharge current which is fed through switching
transistor V230 which is controlled by the processor. Discharging is
indicated by a flashing red LED (V331). The battery is discharged to +5V
and thereafter charged normally to full capacity.
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Technical Documentation
Microphone Amplifier and Corresponding Switches
Transistor amplifier circuit V420 and the corresponding resistors and
capacitors supply bias current for the microphone. Operational amplifier
N430–B amplifies the microphone signal before it is fed to the phone. The
gain of the op amp is approximately 38 dB.
The HF microphone signal is fed to the phone via analogue switches
D400–B and D400–C. The microphone signal XMIC, from the data
accessory (X510) is fed to the phone via switches D400–A and D400–C.
The supply voltage for the amplifier and the analogue switches is taken
from the +5VAN regulator N102. The +VAREF reference voltage is
derived from the N430–A and the +5VAN analogue voltage.
Speaker Amplifier and Corresponding Switches
The XEAR signal from the phone is fed to the HF speaker via analogue
switches D410–C and D410–B. The XEAR signal is amplified about 23dB
(+39dB via amplifier N460, –1dB via the analogue switches, and –15dB
via resistors R460 and R461). The XEAR signal from the phone can be
fed to data accessory (X510) via analogue switches D410–C and D410–A.
The supply voltage +10VAS for the speaker amplifier is derived from the
regulator N100.
Circuit Description (DC4H)
The DC4H–module electronics comprise noise reduction components
only. ’Spark gaps’ E1, E2, E4 and E8 protect against electrostatic
discharge. Refer to Figure 6 – Circuit Diagram (sheet 3).