Datasheet MC33340DR2, MC33340EVK Datasheet (MOTOROLA)

Device

Operating

Temperature Range

Package




SEMICONDUCTOR

TECHNICAL DATA

BATTERY FAST CHARGE

CONTROLLERS

ORDERING INFORMATION

MC33340D

TA = –25° to +85°C

SO–8

D SUFFIX

PLASTIC PACKAGE

CASE 751

(SO–8)

8

1

(Top View)

PIN CONNECTIONS

Order this document by MC33340/D

V

CC

8V

sen

Input

V

sen

Gate Output

Fast/Trickle Output

Gnd

t1/T

ref

High

t2/T

sen

t3/T

ref

Low

7
6
5

1
2
3
4

P SUFFIX

PLASTIC PACKAGE

CASE 626

8

1

MC33340P Plastic DIP

MC33342D SO–8

MC33342P Plastic DIP

1

MOTOROLA ANALOG IC DEVICE DATA

  


The MC33340 and MC33342 are monolithic control IC’s that are
specifically designed as fast charge controllers for Nickel Cadmium (NiCd)
and Nickel Metal Hydride (NiMH) batteries. These devices feature negative
slope voltage detection as the primary means for fast charge termination.
Accurate detection is ensured by an output that momentarily interrupts the
charge current for precise voltage sampling. An additional secondary
backup termination method can be selected that consists of either a
programmable time or temperature limit. Protective features include battery
over and undervoltage detection, latched over temperature detection, and
power supply input undervoltage lockout with hysteresis. Fast charge holdoff
time is the only difference between the MC33340 and the MC33342. The
MC33340 has a typical holdoff time of 177 seconds and the MC33342 has a
typical holdoff time of 708 seconds.

• Negative Slope Voltage Detection with 4.0 mV Sensitivity

• Accurate Zero Current Battery Voltage Sensing

• High Noise Immunity with Synchronous VFC/Logic

• Programmable 1 to 4 Hour Fast Charge Time Limit

• Programmable Over/Under Temperature Detection

• Battery Over and Undervoltage Fast Charge Protection

• Power Supply Input Undervoltage Lockout with Hysteresis

• Operating Voltage Range of 3.0 V to 18 V

• 177 seconds Fast Change Hold–off Time (MC33340)

• 708 seconds Fast Change Hold–off Time (MC33342)

Simplified Block Diagram

This device contains 2,512 active transistors.

DC

Input

V

CC

Undervoltage
Lockout

Over
T emp
Latch

Battery
Detect

T emp
Detect

Time/
T emp
Select

V

sen

V

sen

Gate

Fast/

Trickle

Voltage to

Frequency

Converter

–

∆

V Detect

Counter

Timer

Battery

Pack

Internal Bias

V

CC

V

CC

Gnd

Q

R
S

t1/T

ref

High

t2/T

sen

t3/T

ref

Low

7

6

5

8

4

3

2

1

High

Low

V

sen

Gate

F/T

Over

Under

t1

t2

t3

t/T

Ck F/V R

Regulator

 Motorola, Inc. 1999 Rev 3

MC33340 MC33342

2

MOTOROLA ANALOG IC DEVICE DATA

MAXIMUM RATINGS

Rating Symbol Value Unit

Power Supply Voltage (Pin 8) V

CC

18 V

Input Voltage Range V

Time/Temperature Select (Pins 5, 6, 7) V

IR(t/T)

–1.0 to V

CC

Battery Sense, Note 1 (Pin 1) V

IR(sen)

–1.0 to VCC + 0.6 or –1.0 to 10

V

sen

Gate Output (Pin 2)
Voltage
Current

V

O(gate)

I

O(gate)

20
50

V

mA

Fast/Trickle Output (Pin 3)

Voltage
Current

V

O(F/T)

I

O(F/T)

20
50

V

mA

Thermal Resistance, Junction–to–Air R

θJA

°C/W
P Suffix, DIP Plastic Package, Case 626 100
D Suffix, SO–8 Plastic Package, Case 751 178

Operating Junction Temperature T

J

+150 °C

Operating Ambient Temperature (Note 2) T

A

–25 to +85 °C

Storage Temperature T

stg

–55 to +150 °C

NOTE: ESD data available upon request.

ELECTRICAL CHARACTERISTICS (V

CC

= 6.0 V , for typical values TA = 25°C, for min/max values TA is the operating

ambient temperature range that applies (Note 2), unless otherwise noted.)

Characteristic

Symbol Min Typ Max Unit

BATTERY SENSE INPUT (Pin 1)

Input Sensitivity for –∆V Detection

–∆V

th

–

–4.0

–

mV

Overvoltage Threshold

V

th(OV)

1.9

2.0

2.1

V

Undervoltage Threshold

V

th(UV)

0.95

1.0

1.05

mV

Input Bias Current

I

IB

–

10

–

nA

Input Resistance

R

in

–

6.0

–

MΩ

TIME/TEMPERA TURE INPUTS (Pins 5, 6, 7)

БББББББББББББББББ

Á

Programing Inputs (Vin = 1.5 V)

Input Current
Input Current Matching

ÁÁÁ

Á

I

in

∆I

in

Á

Á

–24

–

ÁÁÁ

Á

–30

1.0

Á

Á

–36

2.0

ÁÁ

Á

µA

%

Input Offset Voltage, Over and Under Temperature Comparators

V

IO

–

5.0

–

mV

Under Temperature Comparator Hysteresis (Pin 5)

V

H(T)

–

44

–

mV

Temperature Select Threshold

V

th(t/T)

–

VCC –0.7

–

V

INTERNAL TIMING

Internal Clock Oscillator Frequency

f

OSC

–

760

–

kHz

БББББББББББББББББ

Á

V

sen

Gate Output (Pin 2)
Gate Time
Gate Repetition Rate

ÁÁÁ

Á

t

gate

Á

Á

–
–

ÁÁÁ

Á

33

1.38

Á

Á

–
–

ÁÁ

Á

ms

s

БББББББББББББББББ

Á

Fast Charge Holdoff from –∆V Detection

MC33340
MC33342

ÁÁÁ

Á

t

hold

Á

Á

–
–

ÁÁÁ

Á

177
708

Á

Á

–
–

ÁÁ

Á

s

V

sen

GATE OUTPUT (Pin 2)

Off–State Leakage Current (VO = 20 V)

I

off

–

10

–

nA

Low State Saturation Voltage (I

sink

= 10 mA)

V

OL

–

1.2

–

V

FAST/TRICKLE OUTPUT (Pin 3)

Off–State Leakage Current (VO = 20 V)

I

off

–

10

–

nA

Low State Saturation Voltage (I

sink

= 10 mA)

V

OL

–

1.0

–

V

UNDERVOLTAGE LOCKOUT (Pin 8)

Start–Up Threshold (VCC Increasing, TA = 25°C)

V

th(on)

–

3.0

3.1

V

Turn–Off Threshold (VCC Decreasing, TA = 25°C)

V

th(off)

2.75

2.85

–

V

TOTAL DEVICE (Pin 8)

БББББББББББББББББ

Á

Power Supply Current (Pins 5, 6, 7 Open)

Start–Up (VCC = 2.9 V)
Operating (VCC = 6.0 V)

ÁÁÁ

Á

I

CC

Á

Á

–
–

ÁÁÁ

Á

0.65

0.61

Á

Á

2.0

2.0

ÁÁ

Á

mA

NOTES: 1. Whichever voltage is lower.

2.Tested junction temperature range for the MC33340/342: T

low

= –25°CT

high

= +85°C

MC33340 MC33342

3

MOTOROLA ANALOG IC DEVICE DATA

Figure 1. Battery Sense Input Thresholds

versus Temperature

TA, AMBIENT TEMPERATURE (°C)

Figure 2. Oscillator Frequency

versus Temperature

TA, AMBIENT TEMPERATURE (°C)

V

th

, OVER/UNDERVOL TAGE THRESHOLDS (V)

f

OSC

, OSCILLATOR FREQUENCY CHANGE (%)

∆

2.10

2.00

1.90

1.02

1.00

0.98
–50 –25 0 25 50 75 100 125

VCC = 6.0 V

16

8.0

0

–8.0

–16

–50 –25 0 25 50 75 100 125

VCC = 6.0 V

I

sink

, SINK SATURATION (mA)

Figure 3. Temperature Select Threshold Voltage

versus Temperature

Figure 4. Saturation Voltage versus Sink Current

V

sen

Gate and Fast/Trickle Outputs

TA, AMBIENT TEMPERATURE (°C)

V

th(t/T)

, TEMPERATURE SELECT THRESHOLD VOLTAGE (

V

V

OL

, SINK SATURATION VOLTAGE (V)

0

–50 –25 0 25 50 75 100 125

–0.2

–

0.4

–0.6

–0.8

–1.0

VCC = 6.0 V

V

CC

Time mode is selected if any of
the three inputs are above the
threshold.

Temperature mode is selected
when all three inputs are below
the threshold.

Threshold voltage is measured with respect to V

CC

.

3.2

0 8.0 16 24 32 40

2.4

1.6

0.8

0

VCC = 6.0 V
TA = 25

°

C

V

sen

Gate

Pin 2

Fast/Trickle
Pin 3

–50

VCC, SUPPLY VOLTAGE (V)

Figure 5. Undervoltage Lockout Thresholds

versus Temperature

Figure 6. Supply Current

versus Supply Voltage

TA, AMBIENT TEMPERATURE (°C)

V

CC

, SUPPLY VOLTAGE (V)

I

CC

, SUPPLY CURRENT (mA)

3.1

–25 0 25 50 75 100 125

3.0

2.9

2.8

2.7

Startup Threshold

(VCC Increasing)

Minimum Operating Threshold

(VCC Decreasing)

1.0

0 4.0 8.0 12 16

0.8

0.6

0.4

0.2

0

TA = 25°C

MC33340 MC33342

4

MOTOROLA ANALOG IC DEVICE DATA

INTRODUCTION

Nickel Cadmium and Nickel Metal Hydride batteries
require precise charge termination control to maximize cell
capacity and operating time while preventing overcharging.
Overcharging can result in a reduction of battery life as well
as physical harm to the end user. Since most portable
applications require the batteries to be charged rapidly, a
primary and usually a secondary or redundant charge
sensing technique is employed into the charging system. It is
also desirable to disable rapid charging if the battery voltage
or temperature is either too high or too low. In order to
address these issues, an economical and flexible fast charge
controller was developed.

The MC33340/342 contains many of the building blocks
and protection features that are employed in modern high
performance battery charger controllers that are specifically
designed for Nickel Cadmium and Nickel Metal Hydride
batteries. The device is designed to interface with either
primary or secondary side regulators for easy implementation
of a complete charging system. A representative block
diagram in a typical charging application is shown in Figure 7.

The battery voltage is monitored by the V

sen

input that

internally connects to a voltage to frequency converter and

counter for detection of a negative slope in battery voltage. A
timer with three programming inputs is available to provide
backup charge termination. Alternatively, these inputs can be
used to monitor the battery pack temperature and to set the
over and under temperature limits also for backup charge
termination.

Two active low open collector outputs are provided to
interface this controller with the external charging circuit. The
first output furnishes a gating pulse that momentarily
interrupts the charge current. This allows an accurate
method of sampling the battery voltage by eliminating voltage
drops that are associated with high charge currents and
wiring resistances. Also, any noise voltages generated by the
charging circuitry are eliminated. The second output is
designed to switch the charging source between fast and
trickle modes based upon the results of voltage, time, or
temperature. These outputs normally connect directly to a
linear or switching regulator control circuit in non–isolated
primary or secondary side applications. Both outputs can be
used to drive optoisolators in primary side applications that
require galvanic isolation. Figure 8 shows the typical charge
characteristics for NiCd and NiMh batteries.

Figure 7. Typical Battery Charging Application

V

CC

Undervoltage

Lockout

Over
Temp
Latch

Battery
Detect

Temp

Detect

Time/
Temp
Select

V

sen

V

sen

Gate

Fast/

Trickle

Voltage to

Frequency

Converter

–

∆

V Detect

Counter

Timer

Battery

Pack

Internal Bias

V

CC

V

CC

Gnd

Q

R
S

t1/T

ref

High

t2/T

sen

t3/T

ref

Low

7

6

5

8

4

3

2

1

High

Low

V

sen

Gate

F/T

Over

Under

t1

t2

t3

t/T

Ck F/V R

Regulator

Reg Control

DC

Input

Charge

Status

R2

R1

MC33340 or MC33342

2.0 V

1.0 V

R

NTC

R3

R4

SW2

SW1

SW3

2.9 V

30

µ

A

30

µ

A

30

µ

A

0.7 V

R2+R1

ǒ

V

Batt

V

sen

–1

Ǔ

T

MC33340 MC33342

5

MOTOROLA ANALOG IC DEVICE DATA

dV

–∆V

Figure 8. Typical Charge Characteristics for NiCd and NiMh Batteries

CHARGE INPUT PERCENT OF CAP ACITY

1.6

1.5

1.4

1.3

1.2

1.0
0 40 80 120 160

Relative Pressure

1.1

70

60

50

40

30

20

10

CELL TEMPERATURE ( C)

°

CELL VOLTAGE (V)

Temperature

Voltage

T

max

V

max

dt

OPERA TING DESCRIPTION

The MC33340/342 starts up in the fast charge mode when
power is applied to VCC. A change to the trickle mode can
occur as a result of three possible conditions. The first is if the
V

sen

input voltage is above 2.0 V or below 1.0 V . Above 2.0 V
indicates that the battery pack is open or disconnected, while
below 1.0 V indicates the possibility of a shorted or defective
cell. The second condition is when the MC33340/342 detects
a fully charged battery by measuring a negative slope in
battery voltage. The MC33340/342 recognize a negative
voltage slope after the preset holdoff time (t

hold

) has elapsed
during a fast charge cycle. This indicates that the battery
pack is fully charged. The third condition is either due to the
battery pack being out of a programmed temperature range,
or that the preset timer period has been exceeded.

There are three conditions that will cause the controller to

return from trickle to fast charge mode. The first is if the V

sen

input voltage moved to within the 1.0 to 2.0 V range from
initially being either too high or too low. The second is if the
battery pack temperature moved to within the programmed
temperature range, but only from initially being too cold. Third
is by cycling VCC off and then back on causing the internal
logic to reset. A concise description of the major circuit blocks
is given below.

Negative Slope Voltage Detection

A representative block diagram of the negative slope
voltage detector is shown in Figure 9. It includes a
Synchronous Voltage to Frequency Converter, a Sample
Timer , and a Ratchet Counter. The V

sen

pin is the input for the
Voltage to Frequency Converter (VFC), and it connects to the
rechargeable battery pack terminals through a resistive
voltage divider. The input has an impedance of
approximately 6.0 MΩ and a maximum voltage range of
–1.0 V to VCC + 0.6 V or 0 V to 10 V , whichever is lower. The
10 V upper limit is set by an internal zener clamp that
provides protection in the event of an electrostatic discharge.
The VFC is a charge–balanced synchronous type which
generates output pulses at a rate of FV = V

sen

(24 kHz).

The Sample Timer circuit provides a 95 kHz system clock

signal (SCK) to the VFC. This signal synchronizes the F

V

output to the other Sample Timer outputs used within the
detector. At 1.38 second intervals the V

sen

Gate output goes

low for a 33 ms period. This output is used to momentarily
interrupt the external charging power source so that a precise
voltage measurement can be taken. As the V

sen

Gate goes
low, the internal Preset control line is driven high for 11 ms.
During this time, the battery voltage at the V

sen

input is
allowed to stabilize and the previous FV count is preloaded.
At the Preset high–to–low transition, the Convert line goes
high for 22 ms. This gates the FV pulses into the ratchet
counter for a comparison to the preloaded count. Since the
Convert time is derived from the same clock that controls the
VFC, the number of FV pulses is independent of the clock
frequency. If the new sample has more counts than were
preloaded, it becomes the new peak count and the cycle is
repeated 1.38 seconds later. If the new sample has two fewer
counts, a less than peak voltage event has occurred, and a
register is initialized. If two successive less than peak voltage
events occur, the –∆V ‘AND’ gate output goes high and the
Fast/Trickle output is latched in a low state, signifying that the
battery pack has reached full charge status.

Negative slope voltage detection starts after 60 ms have
elapsed in the fast charge mode. This does not affect the
Fast/Trickle output until the holdoff time (t

hold

) has elapsed
during the fast charge mode. Two scenarios then exist.
Trickle mode holdoff is implemented to ignore any initial drop
in voltage that may occur when charging batteries that have
been stored for an extended time period. If the negative slope
voltage detector senses that initial drop during the holdoff
time, and the input voltage rises as the battery charges, the
Fast/Trickle output will remain open. However , if the negative
slope voltage detector senses a negative drop in voltage
during the holdoff time and the input voltage never rises
above that last detected level, the Fast/Trickle output will
latch into a low state. The negative slope voltage detector
has a maximum resolution of 2.0 V divided by 1023, or 1.955
mV per count with an uncertainty of ±1.0 count. This yields a
detection range of 1.955 mV to 5.865 mV. In order to obtain
maximum sensing accuracy, the R2/R1 voltage divider must
be adjusted so that the V

sen

input voltage is slightly less than

2.0 V when the battery pack is fully charged. Voltage
variations due to temperature and cell manufacturing must
be considered.

MC33340 MC33342

6

MOTOROLA ANALOG IC DEVICE DATA

Figure 9. Negative Slope Voltage Detector

V

sen

Input

Synchronous

Voltage to

Frequency

Converter

FV = V

sen

(24 kHz)

Ck

Convert

Preset

Trickle Mode

Holdoff

Over Under

Temperature

Charge

Timer

F/T

UVLOHighLow

Battery Detect

Logic

–

∆

V

SCK

95 kHz

V

sen

Gate

V

sen

Gate

Preset

Convert

11 ms

1.38 s

22 ms

Rachet Counter Convert

0 to 1023 FV Pulses

Rachet

Counter

Sample

Timer

MC33340 MC33342

7

MOTOROLA ANALOG IC DEVICE DATA

Fast Charge Timer

A programmable backup charge timer is available for fast
charge termination. The timer is activated by the Time/Temp
Select comparator, and is programmed from the t1/T

ref

High,

t2/T

sen

, and t3/T

ref

Low inputs. If one or more of these inputs
is allowed to go above VCC – 0.7 V or is left open, the
comparator output will switch high, indicating that the timer
feature is desired. The three inputs allow one of seven
possible fast charge time limits to be selected. The
programmable time limits, rounded to the nearest whole
minute, are shown in Figure 10.

Over/Under Temperature Detection

A backup over/under temperature detector is available
and can be used in place of the timer for fast charge
termination. The timer is disabled by the Time/Temp Select
comparator when each of the three programming inputs are
held below VCC – 0.7 V.

Temperature sensing is accomplished by placing a
negative temperature coefficient (NTC) thermistor in thermal
contact with the battery pack. The thermistor connects to the
t2/T

sen

input which has a 30 µA current source pull–up for
developing a temperature dependent voltage. The
temperature limits are set by a resistor that connects from the
t1/T

ref

High and the t3/T

ref

Low inputs to ground. Since all
three inputs contain matched 30 µA current source pull–ups,
the required programming resistor values are identical to that
of the thermistor at the desired over and under trip
temperature. The temperature window detector is composed
of two comparators with a common input that connects to the
t2/T

sen

input.

The lower comparator senses the presence of an under
temperature condition. When the lower temperature limit is
exceeded, the charger is switched to the trickle mode. The
comparator has 44 mV of hysteresis to prevent erratic
switching between the fast and trickle modes as the lower
temperature limit is crossed. The amount of temperature rise
to overcome the hysteresis is determined by the thermistor’s
rate of resistance change or sensitivity at the under
temperature trip point. The required resistance change is:

D

R(T

Low

³

T

High

)

+

V

H(T)

I

in

+

44 mV

30mA

+

1.46 k

The resistance change approximates a thermal hysteresis
of 2°C with a 10 kΩ thermistor operating at 0°C. The under
temperature fast charge inhibit feature can be disabled by
biasing the t3/T

ref

Low input to a voltage that is greater than

that present at t2/T

sen

, and less than VCC – 0.7 V. Under
extremely cold conditions, it is possible that the thermistor
resistance can become too high, allowing the t2/T

sen

input to
go above VCC – 0.7 V , and activate the timer . This condition
can be prevented by placing a resistor in parallel with the
thermistor. Note that the time/temperature threshold of V

CC

– 0.7 V is a typical value at room temperature. Refer to the
Electrical Characteristics table and to Figure 3 for additional
information.

The upper comparator senses the presence of an over
temperature condition. When the upper temperature limit is
exceeded, the comparator output sets the Over Temperature
Latch and the charger is switched to trickle mode. Once the
latch is set, the charger cannot be returned to fast charge,
even after the temperature falls below the limit. This feature
prevents the battery pack from being continuously
temperature cycled and overcharged. The latch can be reset
by removing and reconnecting the battery pack or by cycling
the power supply voltage.

If the charger does not require either the time or
temperature backup features, they can both be easily
disabled. This is accomplished by biasing the t3/T

ref

Low

input to a voltage greater than t2/T

sen

, and by grounding the

t1/T

ref

High input. Under these conditions, the Time/Temp
Select comparator output is low, indicating that the
temperature mode is selected, and that the t2/T

sen

input is

biased within the limits of an artificial temperature window.

Charging of battery packs that are used in portable power
tool applications typically use temperature as the only means
for fast charge termination. The MC33340/342 can be
configured in this manner by constantly resetting the –∆V
detection logic. This is accomplished by biasing the V

sen

input to
≈1.5 V from a two resistor divider that is connected between
the positive battery pack terminal and ground. The V

sen

Gate

output is also connected to the V

sen

input. Now, each time

that the Sample Timer causes the V

sen

output to go low, the

V

sen

input will be pulled below the undervoltage threshold of

1.0 V. This causes a reset of the –∆V logic every 1.38
seconds, thus disabling detection.

Operating Logic

The order of events in the charging process is controlled
by the logic circuitry. Each event is dependent upon the input
conditions and the chosen method of charge termination. A
table summary containing all of the possible operating modes
is shown in Figure 11.

Figure 10. Fast Charge Backup Termination Time/Temperature Limit

Backu

Programming Inputs

Time Limit

Backup

Termination

Mode

t3/T

ref

Low

(Pin 5)

t2/T

sen

(Pin 6)

t1/T

ref

High

(Pin 7)

Time Limit

Fast Charge

(Minutes)

Time Open Open Open 283
Time Open Open Gnd 247
Time Open Gnd Open 212
Time Open Gnd Gnd 177
Time Gnd Open Open 141
Time Gnd Open Gnd 106
Time Gnd Gnd Open 71

Temperature 0 V to VCC – 0.7 V 0 V to VCC – 0.7 V 0 V to VCC – 0.7 V Timer Disabled

MC33340 MC33342

8

MOTOROLA ANALOG IC DEVICE DATA

Figure 11. Controller Operating Mode Table

Input Condition Controller Operation

V

sen

Input Voltage:

>1.0 V and <2.0 V

The divided down battery pack voltage is within the fast charge voltage range. The charger switches from
trickle to fast charge mode as V

sen

enters this voltage range, and a reset pulse is then applied to the

timer and the over temperature latch.

>1.0 V and <2.0 V with
two consecutive –∆V
events detected after 160 s

The battery pack has reached full charge and the charger switches from fast to a latched trickle mode.
A reset pulse must be applied for the charger to switch back to the fast mode. The reset pulse occurs
when entering the 1.0 V to 2.0 V window for V

sen

or when VCC rises above 3.0 V.

<1.0 V or >2.0 V The divided down battery pack voltage is outside of the fast charge voltage range. The charger switches

from fast to trickle mode.

Timer Backup:

Within time limit

The timer has not exceeded the programmed limit. The charger will be in fast charge mode if V

sen

and

VCC are within their respective operating limits.

Beyond time limit The timer has exceeded the programmed limit. The charger switches from fast to a latched trickle mode.

T emperature Backup:

Within limits

The battery pack temperature is within the programmed limits. The charger will be in fast charge mode if
V

sen

and VCC are within their respective operating limits.

Below lower limit The battery pack temperature is below the programmed lower limit. The charger will stay in trickle mode

until the lower temperature limit is exceeded. When exceeded, the charger will switch from trickle to fast
charge mode.

Above upper limit The battery pack temperature has exceeded the programmed upper limit. The charger switches from fast

to a latched trickle mode. A reset signal must be applied and then released for the charger to switch back
to the fast charge mode. The reset pulse occurs when entering the 1.0 V to 2.0 V window for V

sen

or

when VCC rises above 3.0 V.

Power Supply Voltage:

VCC >3.0 V and <18 V

This is the nominal power supply operating voltage range. The charger will be in fast charge mode if
V

sen

, and temperature backup or timer backup are within their respective operating limits.

VCC >0.6 V and <2.8 V The undervoltage lockout comparator will be activated and the charger will be in trickle mode. A reset

signal is applied to the timer and over temperature latch.

Testing

Under normal operating conditions, it would take 283
minutes to verify the operation of the 34 stage ripple counter
used in the timer. In order to significantly reduce the test time,
three digital switches were added to the circuitry and are
used to bypass selected divider stages. Entering each of the
test modes without requiring additional package pins or
affecting normal device operation proved to be challenging.
Refer to the timer functional block diagram in Figure 12.

Switch 1 bypasses 19 divider stages to provide a 524,288
times speedup of the clock. This switch is enabled when the
V

sen

input falls below 1.0 V. Verification of the programmed
fast charge time limit is accomplished by measuring the
propagation delay from when the V

sen

input falls below 1.0 V ,
to when the F/T output changes from a high–to–low state.
The 71, 106, 141, 177, 212, 247 and 283 will now correspond
to 8.1, 12.1, 16.2, 20.2, 24.3, 28.3 and 32.3 ms delays. It is
possible to enter this test mode during operation if the
equivalent battery pack voltage was to fall below 1.0 V. This
will not present a problem since the device would normally
switch from fast to trickle mode under these conditions, and

the relatively short variable time delay would be transparent
to the user.

Switch 2 bypasses 11 divider stages to provide a 2048
times speedup of the clock. This switch is necessary for
testing the 19 stages that were bypassed when switch 1 was
enabled. Switch 2 is enabled when the V

sen

input falls below

1.0 V and the t1/T

ref

High input is biased at –100 mV.
Verification of the 19 stages is accomplished by measuring a
nominal propagation delay of 338.8 ms from when the V

sen

input falls below 1.0 V, to when the F/T output changes from
a high–to–low state.

Switch 3 is a dual switch consisting of sections “A” and “B”.
Section “A” bypasses 5 divider stages to provide a 32 times
speedup of the V

sen

gate signal that is used in sampling the
battery voltage. This speedup allows faster test verification of
two successive –∆V events. Section “B” bypasses 1 1 divider
stages to provide a 2048 speedup of the trickle mode holdoff
timer. Switches 3A and 3B are both activated when the t1/T

ref

High input is biased at –100 mV with respect to Pin 4.

MC33340 MC33342

9

MOTOROLA ANALOG IC DEVICE DATA

Figure 12. Timer Functional Block Diagram

Oscillator

760 kHz

÷

2

3

÷

2

6

÷

2

3

÷

2

1

÷

2

5

÷

2

8

÷

2

2

÷2÷2÷2÷

2

NormalTest

Switch 2

2

11

Switch 3A

2

5

95 kHz
SCK to

Voltage to

Frequency

Converter

Fast/Trickle Output

Time and Test Decoder

Each test mode bypass switch is shown
in the proper position for normal charger operation.

÷

2

2

t1/T

ref

High

t3/T

ref

Low

t2/T

sen

Switch 3B

2

11

Switch 1

2

19

Q Q 22 ms Convert

11 ms Preset

Holdoff Time Signal

D

MC33340

MC33342

Figure 13. Line Isolated Linear Regulator Charger

This application combines the MC33340/342 with an adjustable three terminal regulator to form an isolated secondary side battery charger. Regulator IC2 operates
as a constant current source with R7 setting the fast charge level. The trickle charge level is set by R5. The R2/R1 divider should be adjusted so that the V

sen

input
is less than 2.0 V when the batteries are fully charged. The printed circuit board shown below will accept the several TO–220 style heatsinks for IC2 and are all
manufactured by AAVID Engineering Inc.

V

CC

Undervoltage

Lockout

Over
Temp
Latch

Battery
Detect

Temp

Detect

Time/Temp

Select

V

sen

V

sen

Gate

Fast/

Trickle

Voltage to

Frequency

Converter

–

∆

V Detect

Counter

Timer

Battery

Pack

Internal Bias

V

CC

V

CC

Gnd

Q

R
S

t1/T

ref

High

t2/T

sen

t3/T

ref

Low

7

6

5

8

4

3

2

1

High

Low

V

sen

Gate

F/T

Over

Under

t1

t2

t3

t/T

Ck F/V R

DC

Input

D1

Charge

Status

R2

R1

IC1 MC33340 or MC33342

2.0 V

1.0 V

R

NTC

10 k

R3

R4

SW2

SW1

SW3

2.9 V

30

µ

A

30

µ

A

30

µ

A

0.6 V

C2

0.1

D3

R5

1.0 k

1N4002

D2

C1

0.01

R7

2.4

R8

220

I

Adj

R6

1.8 k

AC

Line

Input

R2

+

R1

ǒ

V

Batt

V

sen

–1

Ǔ

I

chg(fast)

+

V

ref

)

(I

Adj

R8)

R7

I

chg(trickle)

+

Vin–V

f(D3)–VBatt

R5

LM317

IC2

D4

MC33340 MC33342

10

MOTOROLA ANALOG IC DEVICE DATA

AAVID # θSA °C/W
592502B03400 24.0
593002B03400 14.0
590302B03600 9.2

Figure 14. Printed Circuit Board and Component Layout

(Circuit of Figure 13)

MC33340

2.25

″

1.70

″

C2

(Top View) (Bottom View)

Battery
Negative

R

NTC

R

NTC

Battery
Positive

Input
Return

Input
Positive

R5

R6

R1

IC2

IC1

321

Charge Mode

R3

R2
R8

D2

R7

R4

D3

D4

Input

C1

R

NTC

Output

D1

Figure 15. Line Isolated Switch Mode Charger

The MC33340/342 can be combined with any of the devices in the UC3842 family of current mode controllers to form a switch mode battery charger. In this example,
optocouplers OC1 and OC2 are used to provide isolated control signals to the UC3842. During battery voltage sensing, OC2 momentarily grounds the
Output/Compensation pin, effectively turning off the charger . When fast charge termination is reached, OC1 turns on, and grounds the lower side of R3. This reduces
the peak switch current threshold of the Current Sense Comparator to a programmed trickle current level. For additional converter design information, refer to the
UC3842 and UC3844 device family data sheets.

V

Battery

Current Sense

Comparator

Error

Amplifier

V

sen

Gate

Fast/

Trickle

Voltage

Feedback

Input

V

CC

Gnd 5

3

2
1

V

sen

Gate

F/T

2R

R2

R1

1.0 V

1.0 mA

UC3842 Series

Output/

Compensation

R

Primary Circuitry

Secondary Circuitry

Isolation Boundary

MC33340 or MC33342

Gnd 4

2

OC2

OC1

R3

MC33340 MC33342

11

MOTOROLA ANALOG IC DEVICE DATA

Figure 16. Switch Mode Fast Charger

The MC33340/342 can be used to control the MC34166 or MC34167 power switching regulators to produce an economical and efficient fast charger. These devices
are capable of operating continuously in current limit with an input voltage range of 7.5 to 40 V . The typical charging current for the MC34166 and MC34167 is 4.3
A and 6.5 A respectively. Resistors R2 and R1 are used to set the battery pack fast charge float voltage. If precise float voltage control is not required, components
R1, R2, R3 and C1 can be deleted, and Pin 1 must be grounded. The trickle current level is set by resistor R4. It is recommended that a redundant charge termination
method be employed for end user protection. This is especially true for fast charger systems. For additional converter design information, refer to the MC34166 and
MC34167 data sheets.

Q

S

R

V

sen

Gate

Fast/

Trickle

3

V

sen

Gate

F/T

MC33340/342

Gnd 4

2

AC

Line

Input

MC34166 or MC34167

Osc

PWM

Thermal

I

Limit

V

CC

4

2

1

Switch
Output

+

R4

R2

Voltage
Feedback
Input

Battery

Pack

EA

Ref

UVLO

Gnd 3 Compensation 5

C1 R3

R1

MC33340 MC33342

12

MOTOROLA ANALOG IC DEVICE DATA

P SUFFIX

PLASTIC PACKAGE

CASE 626–05

ISSUE K

OUTLINE DIMENSIONS

NOTES:

1. DIMENSION L TO CENTER OF LEAD WHEN
FORMED PARALLEL.

2. PACKAGE CONTOUR OPTIONAL (ROUND OR
SQUARE CORNERS).

3. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.

14

58

F

NOTE 2

–A–

–B–

–T–

SEATING
PLANE

H

J

G

D

K

N

C

L

M

M

A

M

0.13 (0.005) B

M

T

DIM MIN MAX MIN MAX

INCHESMILLIMETERS

A 9.40 10.16 0.370 0.400
B 6.10 6.60 0.240 0.260
C 3.94 4.45 0.155 0.175
D 0.38 0.51 0.015 0.020
F 1.02 1.78 0.040 0.070
G 2.54 BSC 0.100 BSC
H 0.76 1.27 0.030 0.050
J 0.20 0.30 0.008 0.012
K 2.92 3.43 0.115 0.135
L 7.62 BSC 0.300 BSC
M ––– 10 ––– 10
N 0.76 1.01 0.030 0.040

__

D SUFFIX

PLASTIC PACKAGE

CASE 751–05

(SO–8)

ISSUE R

SEATING
PLANE

1

4

58

A0.25MCB

SS

0.25MB

M

h

q

C

X 45

_

L

DIM MIN MAX

MILLIMETERS

A 1.35 1.75

A1 0.10 0.25

B 0.35 0.49
C 0.18 0.25
D 4.80 5.00
E

1.27 BSCe

3.80 4.00

H 5.80 6.20
h

0 7

L 0.40 1.25

q

0.25 0.50

__

NOTES:

1. DIMENSIONING AND TOLERANCING PER ASME
Y14.5M, 1994.

2. DIMENSIONS ARE IN MILLIMETERS.

3. DIMENSION D AND E DO NOT INCLUDE MOLD
PROTRUSION.

4. MAXIMUM MOLD PROTRUSION 0.15 PER SIDE.

5. DIMENSION B DOES NOT INCLUDE MOLD
PROTRUSION. ALLOWABLE DAMBAR
PROTRUSION SHALL BE 0.127 TOTAL IN EXCESS
OF THE B DIMENSION AT MAXIMUM MATERIAL
CONDITION.

D

E

H

A

B

e

B

A1

C

A

0.10

Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty , representation or guarantee regarding
the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and
specifically disclaims any and all liability, including without limitation consequential or incidental damages. “T ypical” parameters which may be provided in Motorola
data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals”
must be validated for each customer application by customer’s technical experts. Motorola does not convey any license under its patent rights nor the rights of
others. Motorola products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other
applications intended to support or sustain life, or for any other application in which the failure of the Motorola product could create a situation where personal injury
or death may occur. Should Buyer purchase or use Motorola products for any such unintended or unauthorized application, Buyer shall indemnify and hold Motorola
and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees
arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that
Motorola was negligent regarding the design or manufacture of the part. Motorola and are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal
Opportunity/Affirmative Action Employer.

Mfax is a trademark of Motorola, Inc.

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