Siemens SLB0587, SLB0587G Datasheet
SLB 0587
Dimmer IC for Halogen Lamps
SLB 0587
Preliminary Data CMOS IC
Features
● Phase control for resistive and inductive loads
● Sensor operation – no machanically moved
switching elements
● Operation possible from several extensions
● Capable of replacing electromechanical wall
switches in conventional light installations
● High interference immunity, even against ripple
control signals
● Programming input for selection of three different func-
P-DIP-8
tions (mode A/B/C)
● Soft start
● Safety turn-OFF
Type Ordering Code Package
SLB 0587 Q67100-A8310 P-DIP-8
SLB 0587 G Q67106-A8315 P-DSO-8-1 (SMD)
P-DSO-8-1
t New Type
For applications where the SLB 0586 A has been used, it is possible to replace the
SLB 0586 A by the SLB 0587 if the appropriate external wiring in accordance with the data
sheet is maintained.
The SLB 0587 is a CMOS IC and the advanced version of the version SLB 0586 A.
The IC permits the design of digital electronic phase controls for operation of incandes-cent
lamps, low-voltage halogen lamps with in-series connected transformers, and universal as well
as split-pole motors.
Semiconductor Group 1
09.94
SLB 0587 SLB 0587 G
SLB 0587
Pin Configuration (top view)
Pin Definitions and Functions
Pin Symbol Function
1
2
3
4
5
6
7
8
V DD
IPROG
IPLL
ISYNC
ISEN
IEXT
SS
V
QT
Reference point (OV)
Programming input
Integrator for PLL
Synchronizing input
Sensor input
Extension input
Supply voltage
Trigger pulse output
Semiconductor Group 2
SLB 0587
Figure 1
Block Diagram
Semiconductor Group 3
SLB 0587
Functional Description
With the SLB 0587 it is possible to generate one defined current pulse per line half cycle.
Together with a triac and a few extra passive components, a line-powered phase-control circuit
can be designed. The phase-control angle (turn-ON time of the triac) can be set on the two
control inputs, pins 5 and 6, of the IC.
The voltage supply to the IC in a two-wire connection is ensured by limiting the angle of current
flow to approx. 152°. This makes it simple to exchange mechanical wall switches in conventional lighting installations. The IC’s internal logic is synchronized with the line by PLL. Thus a
phase control range independent of the line frequency is obtained.
Operation with Low-Voltage Halogen Lamps
In normal, resistive operation of a phase control circuit there is alternately part of the positive
and negative line-voltage half cycle applied to the load via the triac that has started to conduct
because of the trigger pulse. Operation of the circuit with a transformer and low-voltage
halogen lamp connected is largely identical to the operation of a normal filament lamp due to
the primarily resistive nature of the load. In operation with resistive and inductive portions of
load, the zero crossing of the current compared to that of the line voltage line is delayed.
In operation with heavily inductive loads (eg an idling transformer after lamp failure), a highly
lossy state (half cycle operation) can occur after a fault, leading to thermal destruction of the
transformer. Control mechanisms integrated into the SLB 0587 serve to protect the load from
this situation.
If, for instance, a trigger pulse is missing in a half cycle because of a fault, there will be a considerable increase in current in the transformer into the line shortly after the zero crossing of a
voltage wave – after the next firing of the triac at large phase-control angles. If the next trigger
pulse comes into phase when the triac is still conducting because of the inductive current lag,
it has no effect. It is only the subsequent trigger pulse that will fire the triac again.
The case described above, where only one trigger pulse per line cycle leads to firing of the
triac, can turn into a steady-state condition in the absence of further measures.
The SLB 0587 provides the following features to prevent Steady-State Half-Cycle
Operation:
1) Allowance for the conducting state of the triac when setting the trigger pulses. If a
trigger pulse, determined by the set firing angle and status of the internal PLL, coincides with the conducting phase of the triac, the trigger pulse will not be output to the
triac until after the zero crossing of the current wave.
2) Detection of high saturation currents at angles of current flow of more than 180° by
sampling the synchronizing input levels.
If the frequency of such peak situation current exceeds a value defined in the IC,
there will be a safety cut-out.
Semiconductor Group 4
SLB 0587
3) Retriggering if the triac does not remain triggered after the trigger pulse.This can
occur in particular on highly inductive loads (idling transformer with a small magnetizing current) and insensitive triacs. Approx. 1.5 ms (1.25 ms at 60 Hz) after each
trigger pulse from SLB 0587 the conducting state on the triac is sampled via pin 4 of
the IC. If the triac still remains turned off, one-shot retriggering will follow. If the
frequency of retriggering exceeds an internally defined limit value, there will be a
cutout.
Safety Cutout
The purpose of the safety cutout is to prevent thermal destruction of primarily inductive loads
(idling transformer) in the event of very lossy instances of operation. Despite the safety precautions that are integrated, you should only use transformers with thermal protection.
Safety cutout occurs when the count of an 4-bit up/down counter reaches 15. The count is
determined by the ratio of the up/down counting rates. The up-counting rate is the appearance
of high saturation currents and retriggering. A down counting increment is produced when the
count is other than zero at every fifteenth line half-wave. The count is zeroed in the off state
and when short line outages are detected.
Operation (Figure 3)
The integrated circuit can distinguish the instructions ON/OFF and Change of Phase Control
Angle by the duration of sensor touching.
Turning ON/OFF
Short touching (50 to 400 ms) of the sensor area turns the lamp ON or OFF, depending on its
preceding state. The switching process is activated as soon as the sensor is released.
Setting of the Phase Control Angle
If the sensor is touched for a longer period (exceeding 400 ms) the angle of current flow will be
varied continuously. It runs accross the control loop in approximately 7.6 s up and down (e.g.
bright – dark – bright) until the sensor is released.
Easy operation, even in the lower brightness range of incandescent lamps, is enabled by the
following procedure:
The phase control angle is controlled such that the lamp brightness varies physiologically linear with the operating time and pauses for a short period when the minimum brightness is
reached.
Using R
2 and C 4 (synchronizing input) in the application circuit (figure 4), the angle of current
flow can be controlled for purely resistive loads between 45° and 152° of the half-wave.
Semiconductor Group 5
Control Modes of Operation
Mode Period of Touching the Sensor/Extension
Short (60 to 400 ms) Long (more than 400 ms)
SLB 0587
Pre-Touch
A (Pin 2 at V SS) OFF
Max.
Intermediate
B (Pin 2 open) OFF
Max.
Intermediate
C (Pin 2 at V DD) OFF
Max.
Intermediate
Status
Post-Touch
Status
Softstart to Max.
OFF
OFF
Softstart to
stored brightness
from last turn-OFF
OFF
OFF
Softstart to Max.
OFF
OFF
Pre-Touch
Status
OFF
Max./Intermediate
Repeated dimming
OFF
Max./Intermediate
Repeated dimming
OFF
Max./Intermediate
Repeated dimming
Post-Touch
Status
Starts varying at min.
Starts varying at
pre-touch brightness
Same dimming
direction
Softstart to stored
brightness
and varying
Starts varying at
pre-touch brightness
Reversed dimming
direction
Starts varying at min.
Starts varying at
pre-touch brightness
Reversed dimming
direction
Figure 3
Control Behaviour of the 3 Operating Modes
Semiconductor Group 6
SLB 0587
Figure 2
Internal Wiring of Pins
Semiconductor Group 7
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