ON MC33340D, MC33342D, MC33340P, MC33342P Schematic [ru]

MC33340, MC33342

Battery Fast Charge
Controllers

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/Undertemperature Detection

• Battery Over and Undervoltage Fast Charge Protection

• Power Supply Input Undervoltage Lockout with Hysteresis

• Operating Voltage Range of 3.25 V to 18 V

• 177 seconds Fast Change Holdoff Time (MC33340)

• 708 seconds Fast Change Holdoff Time (MC33342)

• Pb−Free Packages are Available

DC

Input

Regulator

Undervoltage

Counter

Timer

Over

Under

4

Lockout

t1

t2

t3

t/T

Time/
Temp Select

R

Q

S

Internal Bias

V

sen

1

V

sen

Gate

2

3

Fast/

Trickle

This device contains 2,512 active transistors.

Voltage to

Frequency

Converter

Battery
Detect

Ck F/V R

High

Low

−DV Detect

V

sen

Gate

F/T

GND

Figure 1. Simplified Block Diagram

Over
Temp
Latch

Temp
Detect

8

V

CC

V

CC

Battery

Pack

t1/T

High

ref

7

t2/T

sen

6

t3/T

Low

ref

5

V

CC

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MARKING

DIAGRAMS

8

PDIP−8

P SUFFIX

8

1

8

1

CASE 626

SOIC−8

NB SUFFIX

CASE 751

x = 0 or 2
A = Assembly Location
L = Wafer Lot
Y = Year
W = Work Week
G = Pb−Free Package

MC3334xP

AWL

YYWW

1

8

3334x

ALYWX

G

1

PIN CONNECTIONS

V

Input

sen

V

Gate Output

sen

Fast/Trickle Output

Gnd

1

2

3

4

(Top View)

8V

CC

t1/T

High

7

ref

6

t2/T

sen

5

t3/T

Low

ref

ORDERING INFORMATION

See detailed ordering and shipping information in the package
dimensions section on page 13 of this data sheet.

© Semiconductor Components Industries, LLC, 2005

July, 2005 − Rev. 7

1 Publication Order Number:

MC33340/D

MC33340, MC33342

MAXIMUM RATINGS (Note 1)

Rating Symbol Value Unit

Power Supply Voltage (Pin 8) V

CC

Input Voltage Range

Time/Temperature Select (Pins 5, 6, 7) V
Battery Sense, (Note 2) (Pin 1) V

V

Gate Output (Pin 2)

sen

Voltage
Current

IR(t/T)

IR(sen)

V

O(gate)

I

O(gate)

−1.0 to VCC + 0.6 or −1.0 to 10

Fast/Trickle Output (Pin 3)

Voltage
Current

Thermal Resistance, Junction−to−Air

V

O(F/T)

I

O(F/T)

R

q

JA

P Suffix, DIP Plastic Package, Case 626 100

D Suffix, SO−8 Plastic Package, Case 751 178
Operating Junction Temperature T
Operating Ambient Temperature (Note 3) T
Storage Temperature T

J

A

stg

Maximum ratings are those values beyond which device damage can occur. Maximum ratings applied to the device are individual stress limit
values (not normal operating conditions) and are not valid simultaneously. If these limits are exceeded, device functional operation is not implied,
damage may occur and reliability may be affected.

1. This device series contains ESD protection and exceeds the following tests:
Human Body Model 2000 V per MIL−STD−883, Method 3015 Machine Model Method 400 V

18 V

−1.0 to V

CC

20
50

mA

20
50

mA

°C/W

+150 °C

−25 to +85 °C

−55 to +150 °C

V

V

V

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2

MC33340, MC33342

Á

Á

Á

Á

Á

Á

Á

Á

Á

Á

Á

Á

Á

Á

Á

Á

Á

Á

Á

Á

Á

Á

Á

Á

Á

Á

Á

Á

Á

Á

ELECTRICAL CHARACTERISTICS (V

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

CC

ambient temperature range that applies (Note 3), unless otherwise noted.)

Characteristic Symbol Min Typ Max Unit

BATTERY SENSE INPUT (Pin 1)

Input Sensitivity for −DV Detection
Overvoltage Threshold
Undervoltage Threshold
Input Bias Current
Input Resistance

TIME/TEMPERATURE INPUTS (Pins 5, 6, 7)

Programing Inputs (Vin = 1.5 V)

ББББББББББББББББ

Input Current

Input Current Matching
Input Offset Voltage, Over and Under Temperature Comparators
Under Temperature Comparator Hysteresis (Pin 5)
Temperature Select Threshold

INTERNAL TIMING

Internal Clock Oscillator Frequency
V

Gate Output (Pin 2)

sen

ББББББББББББББББ

ББББББББББББББББ

Gate Time

Gate Repetition Rate
Fast Charge Holdoff from −DV Detection

ББББББББББББББББ

V

sen

MC33340

MC33342

GATE OUTPUT (Pin 2)
Off−State Leakage Current (VO = 20 V)
Low State Saturation Voltage (I

= 10 mA)

sink

FAST/TRICKLE OUTPUT (Pin 3)

Off−State Leakage Current (VO = 20 V)
Low State Saturation Voltage (I

= 10 mA)

sink

UNDERVOLTAGE LOCKOUT (Pin 8)

Startup Threshold (VCC Increasing, TA = 25°C)
Turn−Off Threshold (VCC Decreasing, TA = 25°C)

TOTAL DEVICE (Pin 8)

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

ББББББББББББББББ

Startup (V
Operating (V

CC

CC

= 2.9 V)

= 6.0 V)

2. Whichever voltage is lower.

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

= −25°CT

low

−DV

th

V

th(OV)

V

th(UV)

I

IB

R

in

I

in

ÁÁÁ

DI

in

V

IO

V

H(T)

V

th(t/T)

f

OSC

t

gate

ÁÁÁ

ÁÁÁ

t

hold

ÁÁÁ

I

off

V

OL

I

off

V

OL

V

th(on)

V

th(off)

I

CC

ÁÁÁ

high

0.95

Á

Á

Á

Á

2.75

Á

= +85°C

−

1.9

−

−

−24

−

−

−

−

−

−

−

−

−

−

−

−

−

−

−

−

−4.0

2.0

1.0
10

6.0

−30

ÁÁÁ

1.0

5.0
44

VCC −0.7

760

ÁÁÁ

33

1.38

ÁÁÁ

177

ÁÁÁ

708

10

1.2

10

1.0

3.0

2.85

0.65

ÁÁÁ

0.61

−

2.1

1.05

−

−

−36

ÁÁ

2.0

−

−

−

−

ÁÁ

−

−

ÁÁ

−

ÁÁ

−

−

−

−

−

3.25

−

2.0

ÁÁ

2.0

mV

V

mV

nA

MW

mA

Á

%

mV
mV

V

kHz

Á

ms

s

Á

s

Á

nA

V

nA

V

V
V

mA

Á

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3

MC33340, MC33342

)

t

sen

V

2.10
VCC = 6.0 V

2.00

1.90

1.02

1.00

, OVER/UNDERVOLTAGE THRESHOLDS (V

0.98

th

V

−50 −25 0 25 50 75 100 125

TA, AMBIENT TEMPERATURE (°C)

Figure 2. Battery Sense Input Thresholds

versus Temperature

0

V

CC

−0.2

−0.4

−0.6

−0.8

−1.0

, TEMPERATURE SELECT THRESHOLD VOLTAGE (

Threshold voltage is measured with respect to VCC.

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.

−50 −25 0 25 50 75 100 125

TA, AMBIENT TEMPERATURE (°C)

VCC = 6.0 V

Figure 4. Temperature Select Threshold Voltage

th(t/T)

V

versus Temperature

16

8.0

0

−8.0

, OSCILLATOR FREQUENCY CHANGE (%Δ

−16

OSC

f

−50 −25 0 25 50 75 100 125

TA, AMBIENT TEMPERATURE (°C)

VCC = 6.0 V

Figure 3. Oscillator Frequency

versus Temperature

3.2
VCC = 6.0 V

TA = 25°C

2.4

V

Gate

sen

Pin 2

1.6

Fast/Trickle
Pin 3

0.8

, SINK SATURATION VOLTAGE (V)

OL

V

0

0 8.0 16 24 32 40

I

, SINK SATURATION (mA)

sink

Figure 5. Saturation Voltage versus Sink Curren

V

Gate and Fast/Trickle Outputs

3.1

Startup Threshold

3.0

2.9

, SUPPLY VOLTAGE (V)

2.8

CC

V

2.7

−50

−25 0 25 50 75 100 125

(VCC Increasing)

Minimum Operating Threshold

(VCC Decreasing)

TA, AMBIENT TEMPERATURE (°C)

Figure 6. Undervoltage Lockout Thresholds

versus Temperature

1.0
TA = 25°C

0.8

0.6

0.4

, SUPPLY CURRENT (mA)

CC

0.2

I

0

0 4.0 8.0 12 16

VCC, SUPPLY VOLTAGE (V)

Figure 7. Supply Current

versus Supply Voltage

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4

MC33340, MC33342

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 u sually a s econdary o r r edundant char ge s ensi ng
technique is employed into the charging system. It is also
desirable to disable rapid charging if the battery voltage or
temperature is either t oo h i gh or too low. In order t o a ddress
these issues , an economical a nd flexi ble fa st char ge c ontroller
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 complet e charging system. A represent ative block d iagram
in a typical charging application is shown in Figure 8.

The battery voltage is monitored by the V

input that

sen

internally connects to a voltage to frequency converter and

Regulator

counter for d etection o f a n egati ve slope in bat tery v ol tage. A
timer with three programming inputs is available to provide
backup charge termi nation. A lternati vely , these input s ca n be
used to monitor the battery pack temperature and to set the
over and undertemperature 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 c urrent. This a llows a n a ccurate m ethod
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 9 shows the typical charge
characteristics for NiCd and NiMh batteries.

DC

Input

Charge

Status

Reg Control

R2

R1

MC33340 or MC33342

Undervoltage

Under

4

Over

t/T

Lockout

Q

t1

t2

t3

Time/
Temp
Select

V

sen

V

sen

Gate

Fast/

Trickle

1

2

3

2.0 V

1.0 V

R2 + R1

Internal Bias

Voltage to

Frequency

Converter

Battery
Detect

V

Batt

ǒ

–1

V

sen

Ck F/V R

High

Low

−DV Detect
Counter

Timer

V

sen

Gate

F/T

Gnd

Ǔ

Figure 8. Typical Battery Charging Application

R

S

Over
Temp
Latch

Temp

Detect

V

8

CC

V

CC

0.7 V

2.9 V

V

30 mA

30 mA

30 mA

CC

t1/T

7

t2/T

6

t3/T

5

ref

sen

ref

Battery

High

Low

Pack

T

SW1

SW3

R

SW2

NTC

R3

R4

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5

MC33340, MC33342

1.6

1.5

1.4

1.3

CELL VOLTAGE (V)

1.2

1.1

1.0
0 40 80 120 160

Figure 9. Typical Charge Characteristics for NiCd and NiMh Batteries

Voltage

Temperature

Relative Pressure

CHARGE INPUT PERCENT OF CAPACITY

OPERATING 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

input voltage is above 2.0 V or below 1.0 V. Above

sen

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

) has elapsed during a fast charge cycle. This

hold

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 10. It includes a
Synchronous Voltage to Frequency Converter, a Sample
Timer, and a Ratchet Counter. The V

pin is the input for

sen

the Voltage to Frequency Converter (VFC), and it connects
to the rechargeable battery pack terminals through a

dt

−DV

70

60

50

40

30

CELL TEMPERATURE ( C)°

20

10

V

max

dV

T

max

resistive voltage divider. The input has an impedance of
approximately 6.0 MW 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

(24 kHz).

sen

The Sample Timer circuit provides a 95 kHz system clock
signal (SCK) to the VFC. This signal synchronizes the F
output to the other Sample Timer outputs used within the
detector. At 1.38 second intervals the V

Gate output goes

sen

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

Gate goes

sen

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

input is

sen

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 F

pulses into the ratchet

V

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 −DV ‘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.

V

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6

MC33340, MC33342

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

) has elapsed

hold

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

FV = V

(24 kHz)

V

sen

Input

Synchronous

Voltage to

Frequency

Converter

SCK

95 kHz

sen

Ck

Convert

Sample

Timer

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 mV, 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
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.

Preset

Rachet

Counter

Trickle Mode

Holdoff

−DV

V

Gate

sen

Battery Detect

Over Under

Temperature

UVLOHighLow

Logic

Charge

Timer

sen

F/T

V

Gate

sen

Preset

11 ms

Convert

22 ms

Rachet Counter Convert

0 to 1023 FV Pulses

Figure 10. Negative Slope Voltage Detector

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
High, t2/T

, and t3/T

sen

Low inputs. If one or more of these

ref

ref

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 Table 1.

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.

1.38 s

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

input which has a 30 mA current

sen

source pull−up for developing a temperature dependent
voltage. The temperature limits are set by a resistor that
connects from the t1/T

High and the t3/T

ref

Low inputs to

ref

ground. Since all three inputs contain matched 30 mA
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

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7

MC33340, MC33342

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:

DR(T

Low

³ T

High

) +

H(T)
I

in

+

44 mV

30 mA

+ 1.46 k

V

The resistance change approximates a thermal hysteresis
of 2°C with a 10 kW thermistor operating at 0°C. The under
temperature fast charge inhibit feature can be disabled by
biasing the t3/T
that present at t2/T

Low input to a voltage that is greater than

ref

, and less than VCC − 0.7 V. Under

sen

extremely cold conditions, it is possible that the thermistor
resistance can become t oo h igh, a llowing t he t2/T

sen

input
to go above VCC − 0.7 V, and activate the timer. This
condition can b e p revented b y p lacing a resistor i n parallel
with the thermistor. Note that the time/temperature
threshold of VCC − 0.7 V is a typical value at room
temperature. Refer to the Electrical Characteristics table
and to Figure 4 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 Overtemperature
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
input to a voltage greater than t2/T
t1/T

High input. Under these conditions, the Time/Temp

ref

, and by grounding the

sen

ref

Low

Select comparator output is low, indicating that the
temperature mode is selected, and that the t2/T

input is

sen

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 −DV
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

Gate output is also connected to the V

sen

each time that the Sample Timer causes the V
low, the V

input will be pulled below the undervoltage

sen

input. Now,

sen

output to go

sen

threshold of 1.0 V. This causes a reset of the −DV 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 Table 2.

Table 1. FAST CHARGE BACKUP TERMINATION TIME/TEMPERATURE LIMIT

Backup

Termination

Mode

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

t3/T

(Pin 5)

ref

Low

Programming Inputs

t2/T

sen

(Pin 6)

t1/T

High

ref

(Pin 7)

Time Limit

Fast Charge

(Minutes)

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8

MC33340, MC33342

Table 2. CONTROLLER OPERATING MODE TABLE

Input Condition Controller Operation

V

Input Voltage:

sen

>1.0 V and <2.0 V

>1.0 V and <2.0 V with
two consecutive −DV
events detected after the

initial holdoff period

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

Timer Backup:

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

Temperature Backup:

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

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

Power Supply Voltage:

VCC >3.0 V and <18 V
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

(t

hold

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

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

)

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

VCC are within their respective operating limits.

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

if V

and VCC are within their respective operating limits.

sen

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

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

or when VCC rises above 3.0 V.

sen

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

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

sen

signal is applied to the timer and over temperature latch.

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

sen

or when VCC rises above 3.0 V.

sen

sen

and

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 11.

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

input falls below 1.0 V. Verification of the programmed

sen

fast charge time limit is accomplished by measuring the
propagation delay from when the V

input falls below

sen

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

1.0 V and the t1/T

High input is biased at −100 mV.

ref

input falls below

sen

Verification of the 19 stages is accomplished by measuring
a nominal propagation delay of 338.8 ms from when the V

sen

input fall s 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

gate signal that is used in sampling

sen

the battery voltage. This speedup allows faster test
verification of two successive −DV events. Section “B”
bypasses 11 divider stages to provide a 2048 speedup of the
trickle mode holdoff timer. Switches 3A and 3B are both
activated when the t1/T

High input is biased at −100 mV

ref

with respect to Pin 4.

http://onsemi.com

9

MC33340, MC33342

Q Q 22 ms Convert

D

11 ms Preset

Oscillator

760 kHz

÷2

Switch 2

11

2

3

÷2

6

÷2

2

÷2

3

÷2

1

Switch 3A

5

2

5

÷2

NormalTest

÷2

8

÷2

2

÷2 ÷2 ÷2 ÷2

Switch 3B

95 kHz
SCK to

Voltage to

Frequency

Converter

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

11

2

Holdoff Time Signal

Switch 1

19

2

MC33340

MC33342

t1/T

ref

t2/T

sen

t3/T

ref

High

Time and Test Decoder

Low

Fast/Trickle Output

Figure 11. Timer Functional Block Diagram

V

V

CC

30 mA

30 mA

30 mA

CC

C2

0.1

t1/T

7

t2/T

6

t3/T

5

ref

sen

ref

Battery

Pack

High

Low

SW1

SW3

V

R5

1.0 k

D3

AC
Line
Input

DC

Input

LM317

I

Adj

IC2

1N4002

D2

R7

2.4

R2

R1

V

C1

0.01

sen

1

R8

220

R6

1.8 k

D1

Charge

Status

R2 + R1

I

chg(fast)

I

chg(trickle)

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

sinks for IC2 and are all manufactured by AAVID Engineering Inc.

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 heat-

sen

D4

V

sen

Gate

2

V

Batt

ǒ

+

V

+

sen

V

ref

–1

) (I

Vin–V

R7

Ǔ

Adj

f(D3)

R5

R8)

–V

3

Fast/

Trickle

Batt

Internal Bias

2.0 V

1.0 V

IC1 MC33340 or MC33342

Voltage to

Frequency

Converter

Ck F/V R
High

Battery
Detect

Low

−DV Detect
Counter

Timer

V

sen

Gate

F/T

Gnd

Undervoltage

Over

Under

t1

t2

t3

t/T

4

Lockout

R

Q

S

Temp

Detect

Time/Temp

Select

Over
Temp
Latch

8

CC

2.9 V

0.6 V

R
10 k

SW2

NTC

R3

R4

Figure 12. Line Isolated Linear Regulator Charger

http://onsemi.com

10

MC33340, MC33342

Input
Return

Input
Positive

Input

AAVID #

q

SA

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

2.25″

Charge Mode

R

R4

D1

C1

R1

D4

R5

R6

D3

IC2

321

R3

IC1

R2
R8

NTC

Output

C2

D2

R7

Battery
Negative

R

NTC

R

NTC

Battery
Positive

MC33340

1.70″

(Top View) (Bottom View)

Figure 13. Printed Circuit Board and Component Layout

(Circuit of Figure 12)

UC3842 Series

V

CC

R2

R1

Voltage

Feedback

Input

Output/

Compensation

1.0 mA
2R

2

Error

Amplifier

1

1.0 V

R

Current Sense

Comparator

Gnd 5

Primary Circuitry

Isolation Boundary

Secondary Circuitry

V

sen

Gate

R3

OC2

OC1

V

Battery

V

sen

Gate

MC33340 or MC33342

2

3

Fast/

Trickle

F/T

Gnd 4

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.

Figure 14. Line Isolated Switch Mode Charger

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11

MC33340, MC33342

MC34166 or MC34167

I

Limit

OSC

S

Q

R

PWM

Thermal

UVLO

Gnd 3 Compensation 5

Ref

EA

C1 R3

V

sen

Gate

2

3

Fast/

Trickle

V

CC

+

4

Switch
Output

2

Voltage
Feedback
Input

1

R1

MC33340/342

R2

Battery

Pack

V

sen

Gate

F/T

AC

Line

Input

R4

Gnd 4

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.

Figure 15. Switch Mode Fast Charger

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12

MC33340, MC33342

ORDERING INFORMATION

Device Package Shipping

MC33340D SO−8
MC33340DG SO−8

(Pb−Free)
MC33340DR2 SO−8
MC33340DR2G SO−8

(Pb−Free)
MC33340P PDIP−8
MC33340PG PDIP−8

(Pb−Free)
MC33342D SO−8
MC33342DG SO−8

(Pb−Free)
MC33342DR2 SO−8
MC33342DR2G SO−8

(Pb−Free)
MC33342P PDIP−8
MC33342PG PDIP−8

(Pb−Free)

†For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging

Specifications Brochure, BRD8011/D.

98 Units / Rail

2500 / Tape & Reel

1000 Units / Rail

98 Units / Rail

2500 / Tape & Reel

1000 Units / Rail

†

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13

NOTE 2

−T−

SEATING
PLANE

H

58

−B−

14

F

−A−

C

N

D

G

0.13 (0.005) B

MC33340, MC33342

PACKAGE DIMENSIONS

PDIP−8

P SUFFIX

CASE 626−05

ISSUE L

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.

DIM MIN MAX MIN MAX

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

L

J

K

M

M

A

T

M

M

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

INCHESMILLIMETERS

__

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14

−Y−

−Z−

MC33340, MC33342

PACKAGE DIMENSIONS

SOIC−8 NB

CASE 751−07

ISSUE AG

NOTES:

−X−
A

58

B

1

S

0.25 (0.010)

4

M

M

Y

K

G

N

C

SEATING
PLANE

0.10 (0.004)

H

D

0.25 (0.010) Z

M

SXS

Y

X 45

_

M

J

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

2. CONTROLLING DIMENSION: MILLIMETER.

3. DIMENSION A AND B DO NOT INCLUDE
MOLD PROTRUSION.

4. MAXIMUM MOLD PROTRUSION 0.15 (0.006)
PER SIDE.

5. DIMENSION D DOES NOT INCLUDE DAMBAR
PROTRUSION. ALLOWABLE DAMBAR
PROTRUSION SHALL BE 0.127 (0.005) TOTAL
IN EXCESS OF THE D DIMENSION AT
MAXIMUM MATERIAL CONDITION.

6. 751−01 THRU 751−06 ARE OBSOLETE. NEW
STANDARD IS 751−07.

MILLIMETERS

DIMAMIN MAX MIN MAX

4.80 5.00 0.189 0.197

B 3.80 4.00 0.150 0.157
C 1.35 1.75 0.053 0.069
D 0.33 0.51 0.013 0.020
G 1.27 BSC 0.050 BSC
H 0.10 0.25 0.004 0.010
J 0.19 0.25 0.007 0.010
K 0.40 1.27 0.016 0.050

M 0 8 0 8

____

N 0.25 0.50 0.010 0.020
S 5.80 6.20 0.228 0.244

INCHES

SOLDERING FOOTPRINT*

1.52

0.060

7.0

0.275

0.6

0.024

*For additional information on our Pb−Free strategy and soldering

details, please download the ON Semiconductor Soldering and
Mounting Techniques Reference Manual, SOLDERRM/D.

4.0

0.155

1.270

0.050

SCALE 6:1

ǒ

inches

mm

Ǔ

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15

MC33340, MC33342

ON Semiconductor and are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice

to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC 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 special, consequential or incidental damages.
“Typical” parameters which may be provided in SCILLC 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. SCILLC does not convey any license under its patent rights
nor the rights of others. SCILLC 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 SCILLC product could create a situation where personal injury or death may occur. Should
Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC 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 SCILLC was negligent regarding the design or manufacture of the part. SCILLC is an Equal
Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner.

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For additional information, please contact your
local Sales Representative.

MC33340/D

16